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chocolate rainbow cake
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Chocolate Rainbow Cake

A rich chocolate bundt cake with a tight, dense crumb and a gorgeous rainbow surprise inside!
Course Dessert
Prep Time 30 minutes
Cook Time 1 hour
Servings 12

Equipment

  • bundt pan or ring mold

Ingredients

Chocolate Rainbow Cake

  • 226 g unsalted butter
  • 75 g refined coconut oil melted or solid
  • 400 g granulated sugar
  • 1 tsp fine sea salt
  • 2 tsps baking powder
  • 2 teaspoon pure vanilla extract
  • 4 large egg whites plus 1 egg yolk
  • 360 g cake flour
  • 250 g plain kefir or buttermilk plus another 20g
  • 40 g dutch process or black cocoa

Chocolate Glaze

  • 1 cup powdered sugar 130g
  • ¼ cup dutch process cocoa
  • ¼ cup milk more as needed
  • Pinch fine sea salt
  • 1 tsp pure vanilla extract

Instructions

  • Preheat oven to 350 F. Butter and flour a large bundt pan.
  • Cream butter, coconut oil, sugar, salt, vanillas and baking powder for a full 5 minutes until very light and fluffy.
  • With the mixer on, add egg whites, one at a time allowing each to be fully incorporated before adding another.
  • Add the sifted flour mixture then turn the mixer on low and slowly drizzle in the buttermilk.
  • In 5 separate bowls, add 1/3 cup of batter. Using gel food coloring add red, yellow, green, blue and purple to each bowl and stir to combine the colors.
  • To the remaining batter add the cocoa, egg yolk and additional buttermilk. Mix to combine.
  • Use most of the cocoa batter to fill your bundt pan. Leave the last bit for the top, to cover the rainbow.
  • Place each of the colored batters in a piping bag (you'll have five) and snip off the top. Use the back of a teaspoon to create a moat in the chocolate batter.
  • Pipe a red circle into the moat then use the back of a spoon to smooth it out so that it's as wide as possible while still leaving a white border on the inner and outer rim.
  • Now add the yellow, leaving a red border on either side. Each following color will decrease in width - see photos above. Spoon the rest of the chocolate batter on top with an offset spatula, careful not to smoosh the rainbow.
  • Bake for 45 minutes, checking for doneness at 40. The bundt is done when you can touch it and it springs back.
  • Allow cake to cool in pan for about 15 minutes, then invert onto a cooling rack.