Ingredients:

  • 2 cups (250g) all-purpose flour
  • 1 ½ cups (300g) granulated sugar
  • 1 tbsp (12g) baking powder
  • ½ tsp (3g) salt
  • ½ cup (113g) unsalted butter, softened
  • ¼ cup (60ml) vegetable oil
  • 2 large eggs
  • 1 cup (240ml) whole milk, room temperature
  • 2 tsp (10ml) pure vanilla extract
  • 1 cup (225g) unsalted butter, softened
  • 4 cups (480g) powdered sugar, sifted
  • 3 tbsp (45ml) heavy cream
  • 2 tsp (10ml) pure vanilla extract
  • 1 pinch (1g) salt
  • ½ cup (60g) rainbow nonpareil sprinkles

Instructions:

  1. Preheat oven to 350°F (175°C). Line a 9x13 inch baking pan with parchment paper.
  2. Beat softened butter and sugar until pale and fluffy (about 3 minutes).
  3. Beat in eggs one at a time, then stir in vegetable oil and vanilla extract until smooth.
  4. Alternate adding dry ingredients (flour, baking powder, salt) and milk, beginning and ending with flour. Mix until just combined.
  5. Pour batter into the pan and bake for 25-30 minutes or until a toothpick comes out clean.
  6. Allow cake to cool completely in the pan before lifting it out via the parchment.
  7. Beat softened butter for 2 minutes until creamy and white.
  8. Add powdered sugar one cup at a time on low speed, then increase to medium-high for 2 minutes.
  9. Mix in heavy cream, vanilla, and salt. Beat on high for another 60 seconds.
  10. Cut circular cake rounds using a 3-inch cutter, layer with buttercream in dessert cups, and top with rainbow nonpareil sprinkles.