Rainbow Cake with Robin’s Egg Blue Frosting
Makes: 1, 8-inch, 4-layer cake
  • 1½ cups (340 g) unsalted butter, at room temperature, plus more for the pans
  • 3 cups (700 g) granulated sugar
  • 3 large eggs, beaten
  • 1½ cups (375 ml) non-fat plain Greek yogurt, or full-fat sour cream
  • 1½ teaspoons vanilla extract or almond extract
  • 3 cups (260 g) sifted cake flour
  • 2 teaspoons baking powder
  • ½ teaspoon fine salt
  • Gel food coloring, as desired
  • 1 recipe Swiss Meringue Buttercream Frosting (or we recommend our Italian Meringue Buttercream), tinted robin’s egg blue (with Wilton gel color Teal)
  1. Preheat the oven to 350°F (180°C). Butter four 8-inch (20-cm) round cake pans and set them aside.
  2. In the bowl of an electric mixer on low speed, cream together the butter and granulated sugar for 5 to 7 minutes until light and fluffy. Beat in the eggs, sour cream, and vanilla. Then beat in the flour, baking powder, and salt for 1 minute, scraping down the sides of the bowl.
  3. Set out four small bowls. Spoon ¾ to 1 cup (about 453 grams) of the batter into each bowl and tint each with food coloring to your desired color, such as pale yellow, green, coral, and pink. Keep in mind that the color will somewhat darken and brown during baking. Spoon a bowl of tinted cake batter into each of the prepared pans and smooth the tops with a spatula or knife.
  4. Bake for 25 to 28 minutes or until the cake comes away from the sides of the pan and is springy to the touch in the center. Remove the cakes from the oven and let them cool in the pan for 15 minutes, then invert them onto cooling racks to cool completely, about 30 minutes.
  5. To assemble the cake, save the most domed layer for the top. Place the flattest layer on a serving plate and spread the top with ½ cup (125 ml) of the frosting. Place another layer on top and frost the top of that layer with another ½ cup (125 ml) of frosting. Place the third layer on top and frost it with another ½ cup (125 ml) of frosting. Place the last layer on top of the stack. Using an offset spatula, frost the sides of the cake with half of the remaining frosting, then use the rest for the top of the cake.
  6. Slice and serve. Store the cake, covered, at room temperature for up to 3 days.
Recipe by Bakepedia at https://www.bakepedia.com/rainbow-cake-with-robins-egg-blue-frosting/