Rainbow Chocolate Cake

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The bright colors and rich, dark chocolate flavor of this gorgeous rainbow chocolate cake will make your birthday party or other special event a day to remember! It looks super fancy, but is actually pretty easy to make. Anyone can make this rainbow chocolate cake recipe and look like a total baking expert!

Don’t be intimidated by the looks of this rainbow cake with chocolate ganache. Even if you are not an experienced baker, you’ll be able to follow the instructions and make a delicious and beautiful cake!

The flavor of this cake stands firmly on its own, but you can pair it with vanilla or even caramel ice cream. Try my caramel nice cream recipe if you want to add something healthy and delicious! You could also pair this 5 layer cake with chocolate banana ice cream or mango nice cream.

This beautiful cake will be the talk of your party and everyone will be asking you how to make rainbow layered cake once they taste it!

👩🏽‍🍳 Why This Recipe Works

• Look super fancy, but is easy to make
• Serves 16-20 people!
• Will make you look like an expert baker
• Kid friendly
• Rainbow layers!
• Beautiful, intense colors
• Decadent & delicious
• Excellent for a birthday celebration or other special event

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🥘 Ingredients

The key to making this rainbow tier cake easily is to be prepared. The great thing is – all of these ingredients are very common and are available at most grocery stores. Make sure you have all of your ingredients and keep them organized. Make sure to review the instructions before beginning and simply follow them step-by-step. Get all the details on the recipe card at the end of this post.

For The Cake

• Almond Milk: Your batter needs liquid to combine all of the ingredients and to add moisture to your chocolate confetti cake. Soy or regular milk can be used in place of almond milk.
• Lemon Juice: Lemon juice adds a bright, crisp, subtle flavor and allows the cake batter to rise properly.
• Brown Sugar: Brown sugar adds a deep, caramel, or toffee-like flavor to this chocolate rainbow cake recipe.
• Coconut Sugar: Coconut sugar adds sweetness to your rainbow layer cakes.
• Salt: Salt enhances the depth and complexity of other flavors in the cake layers.
• Baking Soda: Baking soda reacts immediately to acidic elements in the cake batter and gives an instant leavening effect.
• Baking Powder: Baking powder does the same thing as baking soda, but continues to do so throughout the baking process as it reacts to the heat.
• Cocoa Powder: Cocoa powder is where the chocolate cake flavor comes from. You can also use dutch-process cocoa.
• All-Purpose Flour: Flour is one of the basic foundational ingredients in this recipe that helps the cake have structure. You can use all purpose flour or cake flour. Cake flour will have an even lighter crumb than all purpose flour.
• Light Flavored Olive Oil: Oil helps ingredients combine and adds the most moisture to this chocolate rainbow cake. You want to choose a light flavored oil so it doesn’t change the flavor of the cake.
• Vanilla Extract: This ingredient is great for not only adding vanilla flavor but also because it enhances all of the other flavors in the cake batter.
• Eggs: Eggs act as a binding agent in this recipe and also add a lot to the depth of the flavor.
• Water: Water adds more moisture to mix the batter.
• Dried Instant Coffee: Coffee is an excellent way to enhance the flavor of any chocolate baked good.

For The Buttercream

• Egg Whites: The egg whites give your buttercream icing a rich texture so you don’t have to oversweeten your icing to get a spreadable texture. Ditch those egg yolks though, and make sure they are not included in the buttercream.
• Powdered Sugar: Powdered sugar is used in buttercream because it is light and dissolves easily without having to overwork the icing.
• Butter: Butter is the main ingredient in buttercream. It gives the icing it’s structure and rich flavor.
• Vanilla Extract: Vanilla flavor is key in buttercream icing and it helps bring out the other flavors as well.
• Food Coloring: This is where your beautiful colors come from for your rainbow cake with chocolate frosting. You’ll need 5 different colors (I chose red, yellow, green, blue and purple). Your buttercream will fill between the layers to create a beautiful over the rainbow cake.

For The Ganache

• Dark Chocolate: You can’t really make chocolate ganache without chocolate! I like using dark chocolate because it makes this ganache rich and decadent, but you can use any type of chocolate you like.
• Heavy Cream: Heavy cream creates a creamy and spreadable ganache to top your rainbow slice cake.

🔪 Instructions

It might look complicated, but making this cake is easy when you take it step by step! Here’s how to make rainbow chocolate cake:

Preheat Oven, Combine Almond Milk And Lemon Juice: Preheat oven to 350 degrees F / 180 C. Line two 6 inch round cake tins a piece of parchment paper and set aside. In a mixing bowl, whisk together the almond milk and lemon juice, set aside.

Mix Dry Ingredients: In a separate large bowl whisk the brown sugar, coconut sugar, salt, baking powder and soda, cocoa powder and flour until well combined.

Add Remaining Wet Ingredients, Combine Wet & Dry: Add the oil, vanilla extract and eggs to the almond milk mixture and whisk. Pour the wet ingredients into the flour mixture, mix until combined.

Mix Instant Coffee and Water, Add To Cake Batter: In a separate bowl mix the boiling water and instant coffee. Stir the coffee mixture into the cake batter and mix until incorporated.

Transfer Cake Batter to Prepared Cake Pan. Pour the cake batter into the prepared cake tins and bake for 35-45 minutes or until an inserted skewer comes out clean.

Cool. Allow to cool in the tins for 10 minutes before removing from cake pans and cooling completely on a cooling wire rack.

Prepare Buttercream. While the cakes are on the cooling rack, prepare the buttercream: Whip the pasteurized egg whites with the powdered sugar for 3 minutes. I recommend using a stand mixer or an electric mixer for this.

Add Butter: Add half the butter to the egg white mixture, whip until smooth. Add remaining butter and vanilla extract, whip for 4-5 minutes.

Slice Cakes: When the cakes are cold slice each cake horizontally into 3 even slices so you have a flat cake layer for each cake. You’ll end up with 6 layers between the two baked cakes.

Add Food Coloring: Divide the buttercream into 5 small bowls and add food coloring, mix well. You’ll end up with 5 colors in the separate bowls that you’ll use to make the rainbow effect in each layer of the cake.

Add Buttercream To Cake: On a cake board or serving plate, spread a the first color of buttercream over the base slice of cake (should be the purple frosting color) using an offset spatula. Top it with another layer of cake. Repeat with the next color and next layer of cake until all cake and frosting has been used.

Prepare The Chocolate Ganache, Ice Cake: Finely chop the dark chocolate and place in to a heat proof bowl. Place the cream into the microwave and heat until steaming. Pour hot cream over the chocolate and stir until smooth. Place melted chocolate mixture in the fridge for 10 minutes to become a little firm but spreadable. Cover the entire layer rainbow cake with ganache – starting with the sides of the cake and finishing with the top. Add rainbow sprinkles to the top of the cake. Serve this chocolate fudge rainbow cake at room temperature. Enjoy!

💭 Expert Tips

• Gel food coloring will give you more vibrant colors in your icing, but keep in mind that most gel food coloring uses artificial colors. Using natural food coloring will avoid any artificial ingredients but the colors may not be as bright.
• You can make this cake up to 2 days in advance if you store it properly, but that means leftovers will not stay fresh as long after serving. From the time the cake is baked, it will be fresh for 3-4 days total.
  • To make this ahead of time, you can make the cake layers and the frosting the day before, and store them separately. Here’s how: bake the cake, let it cool, and slice it into layers. wrap each layer in plastic wrap tightly once they have cooled completely. Place the layers in an airtight container. Make the rainbow frosting layers and store them in 5 separate airtight containers. Store both the cake layers and frosting in the fridge. The next day, let the cake layers and frosting come to room temperature and make your ganache. Then assemble, frost, and serve!
• Room temp ingredients are important; Allow all ingredients to warm to room temperature before beginning, for easy mixing and whisking.
• You must use pasteurized egg whites for the buttercream. Since they’re not being “cooked”, pasteurization is key to avoid bacteria or food poisoning.
• Make sure your cakes are cold before icing them! Otherwise the icing will melt off the cake and won’t hold.
• To save time, you could use a chocolate cake mix for the cake base instead of making it from scratch. It might not have the exact same texture but it should work well enough!
• You can place the ganache in the fridge to firm it up. The ganache needs to be the exact right temperature to make it easy to spread over your chocolate cake with rainbow frosting. If the ganache is too soft to work with, place it into the fridge for a little longer to become firmer. If it’s too firm, let it sit out at room temperature for a little while until it’s the right consistency for spreading.
• If you prefer white chocolate to dark, you can make this a white chocolate rainbow cake by using white chocolate instead of dark chocolate for the ganache! You can also replace the cocoa powder with all purpose flour to make your cake vanilla instead of chocolate.

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