Ingredients:

  • 1 ½ cups (192g) all-purpose flour, plus more for dusting the pans
  • 1 ½ teaspoons baking powder
  • ¼ teaspoon baking soda
  • ½ teaspoon salt
  • ½ cup (1 stick, 113g) unsalted butter, softened
  • ¾ cup (150g) granulated sugar
  • 2 large eggs, at room temperature
  • 1 teaspoon vanilla extract
  • ¾ cup (177ml) buttermilk, at room temperature
  • Gel food colouring (red, orange, yellow, green, blue, purple)
  • Sprinkles (optional, for decorating)
  • 1 cup (2 sticks, 226g) unsalted butter, softened
  • 4 cups (480g) powdered sugar, sifted
  • ¼ cup (60ml) heavy cream
  • 2 teaspoons vanilla extract
  • Pinch of salt

Instructions:

  1. Preheat oven to 350°F (175°C). Line a 12-cup muffin tin with cupcake liners.
  2. Whisk together flour, baking powder, baking soda, and salt in a medium bowl.
  3. In a large bowl, cream together butter and sugar until light and fluffy.
  4. Beat in eggs one at a time, then stir in vanilla extract.
  5. Gradually add dry ingredients to the wet ingredients, alternating with the buttermilk, beginning and ending with the dry ingredients. Mix until just combined. Don't overmix!
  6. Divide the batter evenly into six separate bowls. Tint each bowl with a different gel food colouring.
  7. Spoon a small amount of each coloured batter into each cupcake liner, layering the colours to create a rainbow effect. Swirl the colours gently with a toothpick.
  8. Bake for 20-22 minutes, or until a toothpick inserted into the center comes out clean.
  9. Let cupcakes cool in the muffin tin for a few minutes before transferring them to a wire rack to cool completely.
  10. In a large bowl, beat the softened butter until smooth and creamy. Gradually add the powdered sugar, one cup at a time, beating well after each addition.
  11. Beat in heavy cream, vanilla extract, and salt until the frosting is light and fluffy.
  12. Once the cupcakes are completely cool, frost them with the vanilla cloud frosting. Decorate with sprinkles, if desired.