Blue Raspberry Mermaid Cake
Serves: 1 3-layer 8-inch cake
For the Blue Raspberry Rainbow Cake:
  • 2 ¼ cups cake flour
  • 1 ¾ cups all-purpose flour
  • 1 tablespoon baking powder
  • 1 ½ teaspoons fine salt
  • 1 ½ cups (3 sticks, 12 ounces) unsalted butter, cubed and brought to room temperature
  • 2 tablespoons lemon zest
  • 3 cups granulated sugar
  • 6 large eggs, room temperature
  • 1 cup buttermilk
  • ½ cup lemon juice
  • 2 teaspoons vanilla extract
  • ½ teaspoon raspberry extract
  • blue, purple, pink, and orange food gel
For the Blue Raspberry Buttercream:
  • 1 cups (2 sticks, 8 ounces) unsalted butter, room temperature
  • 16 ounces (2 8-ounce packages) cream cheese, room temperature
  • 1 ½ pounds powdered sugar
  • ¾ teaspoon fine salt
  • ¼ cup lemon juice
  • 1 teaspoon vanilla extract
  • ¼ teaspoon raspberry extract
  • Green, blue, pink, and purple food gel
To make the Blue Raspberry Rainbow Cake:
  1. Preheat oven to 350 degrees. Grease three 8-inch cake pans with baking spray, set aside.
  2. Sift flours, baking powder, and salt in a large bowl. Beat butter and lemon zest in a stand mixer fitted with a paddle attachment, about 45 seconds. Scrape bowl, add sugar, beat until light and fluffy, about 2 minutes. Lower speed to medium-low adding eggs, one at a time, beating well after each addition. Scrape bowl and paddle. In a spouted measuring cup whisk together, buttermilk, lemon juice, and extracts.
  3. With mixer's speed on low, add dry mixture in three additions alternately with wet mixture in two additions, beginning and ending with the dry mixture. Give batter a final mix by hand to ensure nothing is stuck to the bowl or paddle.
  4. Divide batter into 4 portions, tint one portion orange, one pink, one purple, and one blue. Spread all of the orange into first pan top orange with ½ of pink. Portion out pink into second pan, topping with ½ of blue batter. Pour purple into bottom of third pan and top with remaining blue batter. Use a butter knife to marble batter. Pan pans against table to release any air bubbles.
  5. Bake for 25 to 30 minutes, rotating halfway. The cake should be slightly golden and toothpick inserted should come out mostly clean with a few moist, not wet, crumbs. Let cakes rest in pans for 5 minutes before inverting onto a wire rack to cool completely.
To make the Blue Raspberry Frosting:
  1. In a stand mixer fitted with a paddle attachment, beat butter and cream cheese on medium-high speed until well blended, about 3 minutes. Gradually add powdered sugar on low speed. Scrape bowl and paddle as needed. Drizzle in lemon juice followed by extracts and salt. Raise speed to medium-high beat for final 30 seconds. Tint ¼ cup yellow, ½ cup pink, ½ cup purple, ½ cup blue and remaining frosting green. Refrigerate until assembly.
To assemble the Blue Raspberry Mermaid Cake:
  1. Dollop a bit of frosting on a cake board. Secure orange-pink cake layer, spread yellow frosting onto layer, secure pink-blue cake layer, spread on even layer of pink frosting, top with blue-purple layer (purple side facing up). Base frost cake with green frosting. Refrigerate for 10 minutes. Frost cake with a final, thicker, coating of green frosting. Refrigerate for a final 10 minutes. Pipe mermaid “scales” on boarder of cake with blue and green frostings. Garnish with pink-purple frosting and sprinkles.
Cake recipe adapted from King Arthur, Frosting by Layer Cake Parade
Recipe by Layer Cake Parade at