Making a Galaxy Cake with Planet Decorations Tutorial

Creating a Galaxy Cake is an enchanting way to add celestial charm to any celebration. The challenge lies in transforming primary cake layers into a mesmerizing, starry night sky with intricate planet decorations.

This blog will teach you to select the right cake recipe, master the techniques for making stunning galaxy frosting, and craft realistic planet embellishments. Step-by-step guidance will illuminate the process of preparing and decorating your cake to achieve a genuinely stellar creation.

Introduction

A Galaxy Cake mirrors the infinite beauty of a star-studded sky, complete with swirling colors and an ethereal glow. You can create this celestial cake using different techniques, with the mirror glaze and buttercream frosting methods being two of the most popular. You can use a classic vanilla cake or any other flavor as a canvas for the vibrant galaxy effect created through colorful decorating techniques.

Importance of Planet Decorations

The addition of planet decorations elevates the cake from a simple, albeit beautiful, dessert to a thematic masterpiece. Typically, you create these planet decorations as cake pops or small cake spheres, adding a 3D effect that makes the cake visually engaging and interactive.

Materials and Tools Needed

Creating a Galaxy Cake requires some specific materials and tools. You will need essentials like 8-inch cake pans, parchment paper, and baking spray. You can use a whisk or stand mixer to blend ingredients like flour, sugar, eggs, butter, milk, and vanilla extract to create the perfect batter. You’ll also need food coloring: black, white, pink, blue, and sometimes purple or Aztec blue.

You will need unsalted butter, powdered sugar, vanilla extract, heavy whipping cream, and gel food coloring for a buttercream galaxy cake. Get ready with additional ingredients like grape jelly, hot water, cold milk, condensed milk, and whipping cream if you want a mirror glaze finish.

An angled spatula, icing smoother, and offset spatula are vital for even frosting. Create starry effects on your galaxy using a food-grade paintbrush splattered with diluted buttercream. Filton Silver Edible Glitter Stars and Silver Sprinkles work wonders for added sparkle. A turntable makes decoration more straightforward and precise, while disposable piping bags and round piping tips are helpful if you need pipe details.

Black cocoa powder with gel food coloring yields a deep black buttercream. You can add the final touches with a small paintbrush, splattering white stars to complete the galactic theme.

Let’s start the galaxy cake preparation journey by baking the cake layers.

Preparing the Cake Layers

Selecting the Perfect Cake Recipe

The first step in making a stunning galaxy cake is selecting the right recipe. Using high-quality ingredients is essential. A kitchen scale can be beneficial to ensure accurate measurements, especially with dry ingredients. The devil’s food or chocolate cake mix works great for the black space cake. If you can’t find devil’s food cake mix, adding black food coloring to chocolate cake mix can achieve that deep, dark hue.

You’ll need a white or vanilla cake mix to divide and color for the planet decorations. If you’re feeling adventurous, you can make your cake from scratch. Recipes like black cocoa cake or gluten-free black cocoa cake offer rich flavors and cater to various dietary needs.

Baking Your Cake Layers to Perfection

Start by lining the cake pans with parchment paper and spraying a minimal baking spray to keep the paper in place to prevent sticking and make it easy to remove after baking. Pour the black cake batter into the pans and place pre-baked colored cake balls in the batter to achieve the galaxy effect.

Gently tap the pans on the counter to release any trapped air bubbles, ensuring an even bake. Bake the cakes according to the recipe instructions. Usually, for 8-inch round pans, baking at 350°F (175°C) for about 24-28 minutes is typical. However, always check for doneness by inserting a toothpick into the center; the cake is ready if it comes out clean.

Cooling and Leveling Your Cake Layers

It’s crucial to cool the cake layers completely. After baking, let the cakes sit for 10-15 minutes, then transfer them to a wire rack. Cooling on a wire rack prevents the cakes from becoming soggy or sticking to the pans.

Once the cakes are thoroughly cooled, level them as the next task. Cakes often expand unevenly during baking, resulting in a dome shape. Use a cake leveler or a serrated knife to level the cakes. 

Watch this tutorial on three different methods for creating galaxy cakes.

Let’s discuss how to make galaxy frosting.

Making the Galaxy Frosting

Creating galaxy frosting is about mastering consistency and blending techniques for a cosmic effect. Let’s dive into the process.

Ingredients for Galaxy Frosting

We’ll use a high-quality buttercream base for our galaxy frosting. Swiss meringue buttercream is a great choice due to its stability and smooth texture. Here’s a basic rundown of what you’ll need: 

• Unsalted butter (room temperature)
• Powdered sugar
• Vanilla extract
• Salt
• Heavy whipping cream
• Gel food coloring (black, blue, pink, white)
• Optional: Black cocoa powder

Creating the Frosting Base

Start by beating the room-temperature butter with a whisk attachment on medium speed until it’s creamy, which should take 2 minutes. Gradually add powdered sugar, one cup at a time, mixing on low speed until thoroughly combined. This prevents the sugar from flying everywhere. Once you incorporate all the sugar, add a pinch of salt, vanilla extract, and heavy whipping cream. Mix until the frosting is smooth and fully integrated into a creamy mixture to achieve an easy-to-spread base.

Mixing Vibrant Galaxy Colors

Divide the buttercream into four bowls. We’ll make four primary colors for our galaxy: black, blue, pink, and white. Use gel food coloring, as it’s more potent and less likely to alter the frosting’s consistency than liquid food coloring. Start with small amounts, mixing well after each addition. If you need a deep black, consider adding black cocoa powder and the black gel color to deepen the color without over-saturating the frosting with food coloring.

Techniques for Galaxy Color Blending

You must blend the colors carefully to achieve that stunning galaxy swirl effect. Here’s one effective method:

1. Piping Bag Method: Spread a piece of saran wrap on your counter. Pipe or spoon rows of the different colored frostings—black, blue, pink, and white—onto the saran wrap. Roll the saran wrap into a log and twist both ends. Slide this log into a piping bag fitted with a tip, such as Wilton Tip #1M. Roll the piping bag between your hands to roughly mix the colors, then pipe onto your cake or cupcakes to create a beautiful marbled effect.
2. Spatula Method: Alternatively, you can randomly spread spoonfuls of the different-colored frostings over your cake. Use a clean spatula to blend the colors until you get a swirled pattern gently. For smoother blending, heat the spatula under hot water before use.

Now that you’ve prepped and readied your cake layers, frost the cake to bring your galaxy-themed creation to life.

Frosting the Cake

Applying a Crumb Coat 

Apply a crumb coat—a thin layer of vanilla buttercream that seals in loose crumbs. This initial layer ensures a smooth surface for the final coat. Put your cake on a turntable to easily access all sides without moving it around. Spread a bit of black Swiss meringue buttercream on the cake board to keep the cake in place.

Cover the top and sides of the cake with vanilla buttercream using an angled spatula. The coat doesn’t need to be perfect, but it covers the entire cake. Refrigerate for 20 minutes to set the buttercream, making the final layer easier to apply.

Adding Galaxy-Inspired Frosting 

Divide your buttercream into separate bowls and use gel food coloring to create vibrant hues like pink, blue, purple, and black. Start with small amounts of gel and add more as needed.

Apply the colors to the cake in patches rather than spreading them evenly. This technique helps create organic, swirled patterns resembling a galaxy. Use a cake spreader, offset spatula, or bench scraper to blend the colors smoothly without over-mixing. Start with lighter shades and layer darker hues to add depth and dimension.

Smoothing and Perfecting Your Frosting 

After achieving a galaxy effect, smooth out the frosting using a bench scraper or offset spatula. This step requires patience; blend the colors until you reach the desired look. If the colors become too dark, add more lighter shades on top.

Dip a small paint brush in diluted white buttercream for fine details like stars and splatter tiny star-like dots onto the cake. Finish with decorative touches like glitter stars or sprinkles. Chill the cake for another 15 minutes to let the frosting set before adding any final decorations.

Read our article for more insight on decorating your cake smoothly using buttercream Icing.

Let’s see how to create planets for the galaxy theme cake.

Creating Planet Decorations

Here’s a step-by-step guide to transforming cake batter into unique planetary decorations that captivate everyone.

Ingredients and Tools for Planets

Essential ingredients and tools:

1. Cake mix or batter: Vanilla or white cake mix is best for dividing and coloring.
2. Food color paste or gel: Choose bright colors like red, yellow, green, blue, purple, and indigo. 
3. Half-sphere molds or cake ball molds: These are essential for forming the planets.
4. Piping bags or ziplock bags: These are useful for handling colored batter.
5. Spoons or angled spatulas: For mixing and transferring the batter.
6. Toothpicks: Handy for adjusting the position of the planets in the cake.
7. Small offset spatula: Helps in smoothing the batter in the molds.
8. Turntable or flat surface: Provides easier access while decorating.
9. Parchment paper or silicone mat: Eases the cleaning process. 
10. Edible glitter or dust: Adds a shimmering effect to the planets.
11. Small candy pieces or sprinkles: For additional texture and detail.

Achieving Realistic Planet Colors

• Divide the batter: Separate the cake batter into small portions.
• Add food color: Start with a few drops. It’s easier to add more than to fix an overly vibrant batch. Mix thoroughly: Ensure the color is uniform and streak-free. For example, mix red and yellow to achieve orange or blue and green for a Martian look.
• Refer to a color chart: This helps plan your palette for a cohesive and realistic outcome. Be gentle to avoid integrating too much air, which may affect the texture.

Shaping Your Planet Decorations

1. Fill the molds: Pour the colored batter into half-sphere or cake ball molds.
2. Grease the molds: Lightly grease the molds to ensure easy release. You can dust silicone molds with flour or cocoa powder.
3. Bake separately: Bake the cake balls or half spheres separately for even cooking.
4. Combine and press: Press cake balls together to form whole planets. Use cake halves for the sides of the main cake.
5. Add to the main batter: Layer the cake balls into the main batter to ensure even placement. Add the batter in phases to prevent floating.

Finishing Touches to Planets

1. Buttercream details: Use black Swiss meringue buttercream for a space-like background that makes the planets pop.
2. Fine details: Use a small piping bag or toothpick for rings, craters, or surface patterns. Edible markers or small decorations like candy rocks provide additional detail.
3. Shimmer and shine: Apply edible glitter or dust for a shiny, realistic finish before the buttercream sets.
4. Starry effect: Spread the black buttercream evenly and add star sprinkles or edible glitter to mimic stars.

Check out our blog on creative planet theme cake ideas.

Watch this detailed step-by-step tutorial on making a solar system cake.

Now that you’ve created the planet decorations, it’s time to think about how to place them on your galaxy cake. 

Placing the Planet Decorations

A little planning here will make a big difference in the final result. Start by visualizing how you want the cake to look when cut. The goal is to have each slice reveal a beautiful, colorful planet inside.

1. Planet Layout: Before adding black cake batter to the pans, pre-place the cake balls or half-sphere molds to determine their positions. Consulting images or models of the solar system can help you decide on the sizes and arrangement of the planets.
2. Embedding Planets into Your Cake: Once you’ve visualized the placement, add a small amount of black cake batter to the pans. Then, insert the cake balls or half-sphere molds into the batter. Gently bang the pans to release any air bubbles, and add the batter in stages to keep the planets from floating to the top. If some planets need to be close to the edges, consider adding those first and filling the batter in phases.
3. Maintaining Cake Stability and Balance: Avoid overly greasy batter, as it might cause the planets to displace. After baking, gently loosen the edges with a knife and cool on a rack. Level the layers to avoid tilting or collapsing. Black Swiss meringue buttercream is excellent for stacking the layers, holding them together, and fitting the galaxy theme. Refrigerate the cake for about 15 minutes to set the buttercream.
4. Final Decorative Touches: Start with a crumb coat and refrigerate the cake for 15 minutes to seal the crumbs. Using a watercolor buttercream technique, apply colors like pink, blue, purple, and black to create a galaxy effect.  Edible glitter stars and sprinkles add extra sparkle. Use a small piping bag or a toothpick to make tiny star dots for a detailed finish. Enhance the realism with textures and patterns resembling nebulae or the Milky Way using shades of gray and black. You can add a glow effect to the planets or label them with a small white buttercream script.

Watch this video, which covers a surprise inside galaxy solar system cake.

Let’s explore the final touches on your galaxy cake and bring all the hard work together into a stunning, edible masterpiece.

Final Touches and Presentation

Sprinkling Edible Glitter and Stars

One crucial aspect is adding edible glitter and stars. Various decorations, such as Wilton Silver Edible Glitter Stars and Silver Sprinkles, can create a captivating sparkling effect. Dip a food-grade paintbrush into diluted vanilla buttercream, then splatter it across the cake to mimic a starry sky. Dip a brush into diluted vanilla buttercream and splatter it across the cake to mimic a starry sky. Sprinkle metallic elements like gold, silver, and copper using luster dust mixed with a bit of alcohol or extract for a more luxurious shimmer. When placing edible glitter stars or sprinkles, press them gently with your fingers to ensure they adhere well to the cake’s surface. Using a small paintbrush, you can also paint individual stars or constellations with a luster dust mixture for added precision and detail.

Inspecting and Making Final Adjustments

After decorating, it’s essential to conduct a final inspection. Ensure the frosting is smooth and the you evenly distribute the colors for galaxy effect. Use a bench scraper or offset spatula to tidy any uneven areas without over-scraping. If any parts look too dark or too light, adjust by adding or blending more colors. Then, chill the cake for 15-20 minutes to set the frosting and make any last-minute tweaks easier.

Presenting and Serving Your Galaxy Cake

Place it on a turntable for easy rotation and optimal viewing from all angles. Ensure it’s fully set and chilled before serving. To enhance the space theme, consider using a decorative stand or plate, possibly dark-colored, to make the galaxy colors pop. Extra touches like planet decorations, star-shaped cookies, or a sprinkle of edible glitter at the base can elevate the overall presentation.

Before serving, dim the lights and use creative lighting like spotlights or string lights to make the glitter sparkle. Take high-quality photos from various angles to capture the cake’s full effect. When cutting the cake, aim to showcase the galaxy design in each slice, perhaps serving them on themed plates with matching napkins and utensils. Place the cake in an airtight container in the refrigerator if you’re not serving it immediately, and allow it to reach room temperature before cutting to enjoy the best flavor and texture.

Frequently Asked Questions

Q. What flavors work best for a Galaxy Cake?

A: Popular flavors include chocolate, vanilla, red velvet, and marble. However, you can choose any flavor since the frosting creates the galaxy design, not the cake itself.

Q. How do I make the galaxy effect on the cake?

A: You can achieve the galaxy effect using buttercream or fondant in shades of blue, purple, pink, and black. Blends these colors to create a swirling, nebula-like appearance and often finishes it with edible glitter or luster dust for a starry effect.

Q. What materials do I need for the planet decorations?

A: You can make the planet decorations using fondant, gum paste, or modeling chocolate. You can use edible paint or food coloring to add details and color to make them look realistic.

Q. Can I make the planet decorations in advance?

A: You can make the planet decorations a few days in advance. Store them in an airtight container in a cool, dry place until you’re ready to use them.

Q. How far in advance can I prepare the Galaxy Cake?

A: You can bake the cake layers 1-2 days ahead and store them wrapped in plastic at room temperature. Decorate the cake the day before serving for the best results.

Q. How should I store the Galaxy Cake?

A: Store the Galaxy Cake in an airtight container in the refrigerator, mainly if it contains perishable fillings or frosting. Let it come to room temperature before serving for the best flavor and texture.

Q. Can I make the cake without fondant?

A: Absolutely! You can create a galaxy effect using buttercream frosting. Simply swirl different colors together with a spatula to achieve the galaxy look.

Q. Are there any specific tools needed to decorate the cake?

A: Basic decorating tools include an offset spatula, icing smoother, piping bags, and food-safe brushes. You may need small cutters, sculpting tools, and edible paints for the planet decorations.

Q. Is a Galaxy Cake suitable for all occasions?

A: Yes, a Galaxy Cake with Planet Decorations is perfect for birthdays, space-themed parties, science events, or anyone fascinated by the cosmos!

Conclusion

Every step is crucial, from preparing the cake bases to mixing vibrant galaxy colors, assembling cake balls as planets, and decorating the cake with swirling celestial designs. A turntable can be your best friend for frosting and decorating all sides of your cake. A bench scraper is excellent for smoothing large areas, and an offset spatula helps with precision in detailed work and creates sharp edges.

The first attempt at blending those cosmic colors might be challenging but keep going. Trying smaller versions or individual components can build your skill. Video tutorials from experts like RoxStarBakes can provide invaluable guidance.

Customize your galaxy cake theme. Adopt a Star Wars theme or an abstract galaxy. Consider using fondant, candy melts, or 3D-printed cake toppers for added detail. Different textures can add more depth to your effect, whether using a textured mat or a palette knife. Join baking communities or forums to share your creations, gain feedback, and learn from others. Baking challenges can also keep you motivated.

If you need more time or want to impress with a professionally made cake, WarmOven is here to help. We offer freshly baked cakes for all occasions, with hassle-free 2-hour doorstep delivery for regular cakes and 1-day delivery for custom creations. Enjoy a 10% discount on orders above ₹700/-. Whether it’s a birthday, anniversary, or special event, WarmOven makes bringing your cake vision to life easy.

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