Rainbow Cake

Beautiful, vibrant and velvety Rainbow Cake layers are hiding rich chocolate filling in them! Topped with silky smooth buttercream frosting and eye pleasing rainbow swirls, this cake is absolutely irresistible! Oh and do not be intimidated, this one is super easy to put together!

I've got loads of other cake recipes if you are looking for some quick and easy options. These are my go-to everyday summer cake recipes: Black Forest Cake, Lemon Coconut Cake Recipe,  Banana Cake Recipe and this single layer Vanilla Cake.

TASTE AND TEXTURE:

• Moist and velvety vanilla flavored cake crumb
• Covered in sweet, creamy and rainbow colored frosting
• Rich chocolate filling between vibrant layers of cake
• Slight crunch from rainbow sprinkles

There's nothing more cheerful than a rainbow cake! Layers and layers of bright, vibrant colors make this cake look like a real masterpiece of cakes.  Silky buttercream frosting and the rich chocolate filling really make this cake THE BEST PARTY DESSERT! 

This cake is perfect for any occasion but I especially like to serve it on birthdays and holidays. It just adds an extra layer of excitement! Tell me, doesn't a Rainbow Birthday Cake sound fun!!

Let's see what you will need to make this pretty rainbow dessert-

CAKE INGREDIENTS:

• Cake Flour - cake flour is finely milled and lighter than all purpose flour. It is also the best flour to use while opting for reverse creaming method to make the cake batter. As cake flours tend to develop less gluten as compared to APF.
• Leaveners- You will require both baking soda and baking powder for this cake recipe. Make sure to use fresh ones as they are crucial for the lift of cake.
• Granulated sugar - pantry staple white granulated sugar gives this cake just the right amount of sweetness.
• Egg whites - you can separate your own eggs or buy egg whites at the grocery store. Both will work well. Using only egg whites removes the yellow tint that comes from yolks.
• Vegetable oil - any mild cooking oil works well. I used canola for this cake.
• Buttermilk - use store bought buttermilk or make your own with regular milk and vinegar. The buttermilk makes the cake soft and springy as it reacts with the baking soda.

FROSTING INGREDIENTS:

• Confectioner's sugar - confectioner's sugar gives the frosting a light fluffy texture
• Whole milk or heavy cream - either of these will add to the creaminess of the frosting

FILLING INGREDIENTS:

• Heavy cream - heavy cream makes the filling really rich and creamy.
• Chocolate - Chocolate gives all the flavor to the filling. So make sure to use good quality chocolate. Preferably with a minimum of 40-60% cacao.

HOW TO MAKE RAINBOW CAKE:

We are using reversed creaming method to create this white velvet cake and then tint it with rainbow food coloring! I haven't opted for typical rainbow colors, these colors are more like neon shades, just like Lisa Frank does it!!

• Remove ingredients from the fridge. Make sure all the ingredients are removed from the fridge and are at room temperature before you begin preparing the cake batter.
• Prepare your pans. Spray pans with cooking spray and place a piece of parchment paper on the bottom.
• Combine a portion of the buttermilk and the oil and set aside. 
• Combine the remaining buttermilk and the other wet ingredients and set aside. 
• Combine the dry ingredients in the bowl of a stand mixer.
• Add butter to the dry ingredients and mix on low.
• Pour in the buttermilk/oil mixture and mix until dry ingredients are moistened.
• Add in the egg white/milk mixture in batches, letting the batter mix for a few seconds each time. Scrape down the sides again to make sure everything has incorporated.
• Divide your batter into 7 bowls. Weigh the same amount of batter for each bowl.
• Add the color. Pour ½ teaspoon of coloring into each bowl.
• Bake your layers. Bake until the cakes pass toothpick test.
• Let cakes cool before flipping them out.
• To assemble the cake: Layer the cakes with chocolate filling and cover in buttercream then. Decorate with swirls and chill the cake in refrigerator for about an hour before serving.

HOW TO MAKE THE FROSTING:

• Beat the butter until creamy in a stand mixer or using a hand mixer.
• Add the confection's sugar and the wet ingredients and mix until the frosting is smooth.

TIPS TO MAKE A PERFECT CAKE EACH TIME:

• Make sure all the ingredients are at room temperature.
• Use any mild flavored cooking oil like canola or vegetable.
• Using only egg whites keep the cake a pure white once baked. This is a good option when you are adding food coloring.
• Make sure the cakes are completely cool and chocolate filling is chilled and set  before you start to assemble them.

What does rainbow cake taste like?

You won't be baking this cake only for the looks, I promise! You will taste a moist, velvety and soft buttermilk vanilla cake in every bite among these vibrant and pretty layers. 

To ensure the layers are distinct and vibrant, we are only using egg whites to make this cake. Yellow color of yolk can interfere with 

Which food coloring is best for rainbow cake?

Gel food coloring will work the best for rainbow cake as it imparts a deeper color. I used chef masters neon colors to color the cake and frosting. Americolor electric colors would work well too.

How do you make vibrant colored icing?

The best way to make vibrant colored icing is to use gel food colorings instead of a water based one. Gel food colorings are oil based and will impart a deeper color using less food coloring. Keep adding color drops until you get the color you are looking for. 

How do you do rainbow piping?

Place your colored frosting one by one in food cling wrap using a spoon (refer picture number 6 above). Then roll the wrap and secure both its ends. Now cut one end and place it in your piping tip fitted piping bag.

Gently squeeze each color down to the tip of the bag so that each color come out with every squeeze. (Check out rainbow cake video for visual).

Quick Tip: I used 4 colors in one piping bag and then the remaining 3 in the other bag. This way the colors on the frosting appear more clearly and don't get mixed up with each other.

How do you make swirls on top of a cake?

To make swirls on top of a cake fill your piping bag with frosting. Hold the piping bag vertically over your cake, about half an inch above the cake. Now start making swirls, going around three times and then lift the tip up. Repeat to cover the top edge of your cake with swirls. 

Quick Tip: I did my swirls at 12, 3, 6, and 9 o’clock order from the first piping bag. Then covered the gaps with 4 more swirls, using the second piping bag. This way you can be sure all the seven colors are beautifully revealed in these 8 swirls.

How long does this cake last?

Rainbow cake will last for up to 3 days on the counter and retain its moisture. If you want it to keep longer then place it in the fridge covered at all times for about a week. You can also freeze this cake with or without frosting for about 2 months. Thaw on counter top before enjoying!

Can you freeze this cake?

It is best to freeze the cake layers before you assemble the cake. When ready to frost, remove from the freezer, thaw cakes, layer with the filling and then frost.

More Fun Desserts you will love:

• Funfetti Cupcakes Recipe
• Vanilla Chocolate Cakesickles
• Giant Birthday Cookie
• Birthday Chocolate Cake

If you liked this rainbow cake recipe, please give it a star review. I would really appreciate it. Also, tell me in the comments below, how did it turn out for you! How did your family or guests like it? And don’t forget to share your wonderful creations with me on Instagram at #greedyeatsblog And let's be friends on Pinterest and Facebook too! 

Recipe

Rainbow Cake

Beautifully moist white velvet Cake layers, dyed in rainbow colors and are hiding rich chocolate filling in them! This Rainbow Cake is topped with silky smooth buttercream frosting and eye pleasing rainbow swirls.

5 from 11 votes

Print Pin Rate

Course: Dessert

Cuisine: American

US Customary - Metric

Prep Time: 15 minutes minutes

Cook Time: 20 minutes minutes

Chilling Time: 1 hour hour 30 minutes minutes

Total Time: 2 hours hours 5 minutes minutes

Servings 16 Slices

1x2x3x

Calories: 723kcal

Author: Neha

Equipment

• 7 6" Round Cake Pans or 6 8" Round Cake Pans
• 1 Hand/stand Mixer
• Chef Masters/Ameri Color Neon/Electric Food Colorings
• Piping Bags and Tips
• Ateco 849 Piping Tip (or Wilton 1M works too)

Ingredients

• ▢ 5 and ½ cups cake flour
• ▢ 680 gms granulated sugar
• ▢ 2 teaspoon salt
• ▢ 2 tbsps baking powder
• ▢ 1 teaspoon baking soda
• ▢ 283 gms egg whites at room temperature
• ▢ 170 ml vegetable oil
• ▢ 510 ml buttermilk at room temperature or slightly warm
• ▢ 1 and ½ cups butter unsalted and softened
• ▢ 1 tablespoon vanilla extract

For Vanilla Buttercream Frosting

• ▢ 1 cup unsalted butter softened to room temperature
• ▢ 3 cups confectioner's sugar
• ▢ ⅔ cup heavy cream (or whole milk)
• ▢ 2 tsps pure vanilla extract
• ▢ ¼ teaspoon salt

For Chocolate Filling

• ▢ 1 cup heavy cream
• ▢ 1 cup good quality chocolate

To Decorate:

• ▢ ½ Cup Rainbow Sprinkles
• ▢ 8 Cherries dipped in edible Glitter
• ▢ Few Rainbow decorative pieces

US Customary - Metric

Instructions

To make Cake:

• Heat oven to 335º F and prepare 7 6" x 2" pans by lining them with parchment paper.
• Mix together half of total buttermilk with 170 ml of oil and set it aside.
• Combine the wet ingredients in a mug/bowl- buttermilk, egg whites, and vanilla together, whisk to break up the eggs and set aside.
• Combine dry ingredients- flour, sugar, baking powder, baking soda and salt in the bowl of a stand mixer, attached with paddle attachment and mix for a few seconds.
• Add softened butter to the dry ingredients and mix on low until the mixture resembles coarse sand.
• Add in milk/oil mixture and mix until ingredients are moistened. Increase speed and mix for 2 full minutes to develop the cake's structure. Don't skimp on this step. Your cake could collapse if not fluffed well at this stage. Scrape down the sides of the bowl as needed.
• Next, pour in egg white/milk mixture in three batches, letting the batter mix for 15 seconds between batches. Give a final mix using a spatula to make sure everything has been incorporated well.
• Now divide batter into 7 bowls equally. A weighing scale comes in super handy for this step. Color each bowl with your neon/electric food colors. I used 1 teaspoon neon pink for the pink layer, ½ teaspoon neon orange for orange layer, ½ teaspoon yellow for yellow layer, ½ teaspoon green for green layer, ½ teaspoon tiffany for blue layer, ½ teaspoon neon purple for the purple layer and ½ teaspoon red for the red layer.
• Bake for 15-20 minutes or until the edges start pulling away from the cake pan and the cakes pass toothpick test. Take cakes out of the oven and tap pan on the countertop to release any steam. This will prevent the layers from shrinking. If you don't have so many pans, bake cakes in 2-3 batches. Wash, dry and prepare pans again before baking the second batch.
• Allow the cakes to cool down for a few minutes inside the pan before flipping them out. They will shrink slightly. Allow to cool completely on a wire rack before frosting.
• Once the cakes are cooled, begin layering the cakes with chocolate filling and quickly chill it. Then crumb coat whole cake with a thin layer of buttercream. Allow the crumb coat to set in refrigerator for about 30-45 minutes. Then frost with buttercream frosting and create swirl effect on the cake with the back of a spoon. place the cake back into the fridge for 15 minutes before you apply rainbow swirls and border on the bottom.
• Finish the cake with rainbow decorations, sprinkles and glittery maraschino cherries.

To make Vanilla Buttercream:

• Using a hand-held/stand mixer fitted with a paddle attachment beat the butter on medium speed in a large bowl until creamy, about 2 minutes.
• Add confectioners’ sugar, heavy cream, vanilla extract, and salt with the mixer running on low. Now, Increase the speed to high speed and beat for 2-3 more minutes.
• Add more confectioners’ sugar if frosting is too thin, more milk if frosting is too thick or an extra pinch of salt if frosting is too sweet.
• Use half the frosting as white vanilla to coat the cake and color the other half for rainbow swirls (check video on how to fill frosting in the piping bag and how to create swirls).

To make the Chocolate Filling:

• Pour heavy cream in a saucepan.
• Stir the cream and heat it until it is hot enough to melt the chocolate. Don't let it come to a boil.
• Now add chocolate and stir until smooth. Allow to cool down and set in the fridge for about 30 minutes. Give it a quick whirl using a whisk and it's ready to be layered.

To fill Rainbow Frosting in piping bag:

• Place your colored frosting one by one in food cling wrap using a spoon (refer picture number 6 above in the post). Then roll the wrap and secure both its ends. Now cut one end off and place it in your Ateco 849 piping tip fitted piping bag.

  Gently squeeze each color down to the tip of the bag so that each color come out with every squeeze. (Check out rainbow cake video for visual).

  Quick Tip: I used 4 colors in one piping bag and then the remaining 3 in the other bag. This way the colors on the frosting appear more clearly and don't get mixed up with each other.

Video

Notes

• Cake Pans: If you don't have so many pans you can prepare the batter at once and bake the cake in 2-3 batches. Store batter in the refrigerator while the first batch is baking.
• Baking in 8 inches Pans- To bake this cake in 8 inches pans, divide the cake batter in 6 bowls, color them with 6 colors instead of 7 and bake cakes for about 20-24 mins at 350 deg F.
• Keep cake chilled while assembling- 1. Always remember to chill your cakes after filling with chocolate cream once for about 30-45 minutes. 2.Once after crumb coating and 3. again after decorating with buttercream and before cutting it to ensure clean slicing. The idea is to keep your cake chilled at all times during the assembling and decorating period. Whenever you realized it's getting warm, stick it in the fridge for a few mins before continuing with the next step!
• Cake Flour- Do not switch cake flour with all purpose flour in this recipe. Cake flour ensures a moister and softer crumb that you are looking for in a rainbow cake!
• Egg Whites- We are not using egg yolks in this batter as the yellow color of yolks can interfere with other food colorings. So don't use yolks in this recipe.
• Food Coloring- I have used chef masters neon colors to color my cakes and frosting. Americolor works wonderfully too!

Nutrition

Serving: 1Slice | Calories: 723kcal | Carbohydrates: 62g | Protein: 6g | Fat: 39g | Sodium: 307mg | Sugar: 42g

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