Ingredients:

  • 2 1/2 cups (300g) all-purpose flour
  • 1 tbsp (12g) baking powder
  • 1/2 tsp (3g) baking soda
  • 1/2 tsp (3g) salt
  • 1 cup (227g) unsalted butter, softened
  • 1 3/4 cups (350g) granulated sugar
  • 3 large eggs
  • 1 tbsp pure vanilla extract
  • 1 1/4 cups (300ml) buttermilk
  • 1/2 cup (60g) rainbow sprinkles, preferably jimmies
  • 1 cup (227g) unsalted butter, softened (for buttercream)
  • 3 cups (360g) powdered sugar, sifted (for buttercream)
  • 1/4 cup (60ml) milk or heavy cream (for buttercream)
  • 1 tbsp pure vanilla extract (for buttercream)
  • Pinch of salt (for buttercream)
  • Extra sprinkles, for decoration (for buttercream)

Instructions:

  1. Preheat oven to 350°F (175°C). Grease and flour two 9-inch cake pans. Line the bottoms with parchment paper rounds.
  2. Whisk together flour, baking powder, baking soda, and salt in a medium bowl.
  3. In a large bowl, cream together the softened butter and sugar until light and fluffy.
  4. Beat in the eggs one at a time, then stir in the vanilla extract.
  5. Gradually add the dry ingredients to the wet ingredients, alternating with the buttermilk, beginning and ending with the dry ingredients. Mix until just combined.
  6. Gently fold in the rainbow sprinkles.
  7. Divide the batter evenly between the prepared cake pans. Bake for 30-35 minutes, or until a wooden skewer inserted into the center comes out clean.
  8. Let the cakes cool in the pans for 10 minutes before inverting them onto a wire rack to cool completely.
  9. Beat the softened butter until smooth and creamy (for buttercream). Gradually add the powdered sugar, beating on low speed until combined.
  10. Beat in the milk or heavy cream, vanilla extract, and salt until light and fluffy (for buttercream).
  11. Once the cakes are completely cool, frost the top of one cake layer with buttercream. Place the second cake layer on top. Frost the entire cake with the remaining buttercream. Decorate with extra sprinkles.