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Unicorn Birthday Cake

Unicorn Birthday Cake Recipe

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Prep Time 45 minutes
Cook Time 1 hour 10 minutes
Total Time 1 hour 55 minutes
Servings: 12 servings
Calories: 460
Ingredients Method Notes

Ingredients
  

  • 1 box (15.25 oz) vanilla cake mix
  • 1 cup buttermilk
  • ½ cup melted unsalted butter
  • 3 large eggs
  • Gel food coloring (red, orange, yellow, green, blue, purple)
  • 1 ½ cups unsalted butter, softened
  • 4 cups powdered sugar
  • ¼ cup sour cream
  • 2 tsp vanilla extract
  • 1 to 2 tbsp milk
  • 1 sugar cone
  • Gold sanding sugar or gold sprinkles
  • White chocolate melting wafers or a bar of white chocolate
  • Rainbow sprinkles

Method
 

  1. Preheat oven to 350°F. Grease two 8-inch pans and line with parchment.
  2. Whisk cake mix, buttermilk, melted butter, and eggs until smooth.
  3. Divide batter evenly into 6 bowls. Color each with one gel color.
  4. Spoon red batter into one pan, spread evenly, and bake 12 to 14 minutes. Cool 5 minutes, then turn out. Repeat for orange, yellow, green, blue, and purple.
  5. Beat softened butter until pale. On low, add powdered sugar, then sour cream, vanilla, and 1 tbsp milk. Adjust milk for spreadable consistency.
  6. Stack layers from purple to red, spreading frosting between each. Frost top and sides.
  7. Coat sugar cone with frosting and gold sprinkles. Melt white chocolate, spread thin, set, and cut into ear triangles.
  8. Press horn and ears onto cake. Scatter sprinkles. Chill 30 minutes before serving if you like a firm frosting.

Notes

Cake mix brands vary slightly in weight, so if your batter seems extra thick, add a tablespoon of buttermilk. The layers cool fast, but you can speed up the process by popping the pans in the fridge for a few minutes after turning out. Allow about 30 minutes for the cake to firm up in the fridge after decorating if you want cleaner slices.