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.
Servings: 16 Slices
Calories: 723kcal
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
- 3 cups unsalted butter softened to room temperature
- 1 cup 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
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