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A peacock cake with a slice being lifted from the cake.
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Rainbow Swirl Cake

A vibrant show-stopping cake that's delicious and surprisingly easy to make! Moist vanilla cake layers covered in creamy Italian meringue buttercream and crowned with white chocolate sails!
Course Dessert
Cuisine American
Prep Time 25 minutes
Cook Time 30 minutes
Total Time 55 minutes
Servings 12
Calories 210kcal
Author John Kanell

Ingredients

INGREDIENTS

For the Cake:

  • 1 2/3 cup all-purpose flour
  • 1 cup sugar
  • 1/4 tsp baking soda
  • 1 tsp baking powder
  • 3/4 cup unsalted butter room temperature
  • 3 egg whites
  • 3 tsp vanilla extract
  • 1/2 cup sour cream
  • 1/2 cup whole milk
  • food coloring

For the Vanilla Buttercream:

  • 1 cup butter
  • 5 cup confectioners' sugar
  • 1/4 cup heavy whipping cream
  • 2 tsp orange blossom water
  • food coloring

For the Italian Buttercream:

  • 4 egg whites
  • 1 1/3 cups sugar
  • pinch kosher salt
  • 16 ounces unsalted butter room temperature
  • 1 tsp vanilla extract
  • 1/4 tsp cream tartar

For the Feathers:

  • 1/2 cup candy melt white, melted

Instructions

INSTRUCTIONS

    For the Cake:

    • Preheat oven to 350 degrees.
    • Sift the dry ingredients together in a large bowl. Beat the wet ingredients together in a medium bowl. Add the wet to the dry and mix until just combined.
    • Evenly divide batter into 6 different batches. Color each with drops of food coloring until desired color is reached. 
      Peacock Cake
    • Transfer batter to piping bags. Use 3 buttered and flowered 6-inch cake pans. 
    • Pipe in dollops of the batter, alternating the colors. You can swirl with a skewer around batter as desired.
    • Bake for 30 minutes.  Let cool for 5 minutes.

    For the Vanilla Buttercream:

    • Beat the butter until light and fluffy. Add the confectioners' sugar and cream and mix.
    • Divide evenly into batches and dye with food coloring.

    For the Italian Buttercream:

    • Beat the egg whites, salt and cream of tartar, slowly add in 1/3 cup of sugar and continue beating until soft peaks form. In a medium saucepan add the remaining sugar and 1/3 cup water then place on medium-low heat.
    • Stir until sugar melts and becomes clear. Maintain at medium-high heat until temperature reads 235-240F.
    • Run mixer until meringue is cool/tepid. Add room temperature butter into running mixer one tablespoon piece at a time. Add the salt and vanilla.
    • Beat until butter is combined and mixture has reached a silky consistency.
    • Reserve about 1/3 cup. Add food coloring for watercolor piping step later. 

    For the Feathers:

    • Add dollops of candy melt to parchment paper. Color with a few drops of food coloring. Using a spoon, spread to achieve a feather like shape. 
      Peacock Cake

    For the Assembly:

    • Pipe vanilla buttercream between the cake layers, alternating colors. 
      Peacock Cake
    • Once the cake has chilled, pipe Italian buttercream on the outside of the cake. With a steady hand, work your way around the cake until it is completely covered. 
      Peacock Cake
    •  Tint with 5 different colors. Dollop on colors with a spoon. Smooth out for a watercolor effect. 
      Peacock Cake
    • Add feathers to the cake.
      Peacock Cake

    Video

    Notes

    • If you’re not using 6-inch pans, double the recipe for 8-inch pans or triple the recipe for 9-inch pans.
    • If you see little clumps of butter after you mix the wet ingredients don’t panic, it all works out by the time you mix in the dry ingredients. You can even use melted butter and warm the milk and sour cream up a bit if you like.
    • You can substitute whole milk yogurt for the sour cream if desired, I do it all the time and can’t really tell the difference.
    • To get FLAT layers that are moist inside and out try using cake strips! You can buy a set online or make your own from foil and paper towels at home. I made a whole blog post on it so check it out if you’re interested!
    • If you don't want to make Italian buttercream you can use the American variety. I just prefer the smoothness and taste of the Italian variety. I know it's a pain to make two different types of frosting though!

    Nutrition

    Calories: 210kcal