Instructions:

• Preheat your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans, or line them with parchment paper for easy release.
• In a medium bowl, whisk together the all-purpose flour, baking powder, and salt.
• In a large mixing bowl, beat together the melted unsalted butter and granulated sugar until light and fluffy.
• Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.
• Gradually add the dry ingredient mixture to the butter mixture, alternating with the buttermilk.
• Gently fold the rainbow sprinkles into the batter.
• Divide the batter evenly between the prepared cake pans. Bake for 25-30 minutes.
• Let the cakes cool in the pans for about 10 minutes, then turn them out onto a cooling rack to cool completely.
• In a large bowl, beat the softened unsalted butter until creamy. Gradually add the powdered sugar and cocoa powder, mixing well.
• Pour in the heavy whipping cream and vanilla extract, and beat until the frosting is smooth.
• Place one cake layer on a serving platter, spread frosting on top, then place the second layer on top and frost the top and sides.
• Decorate with additional sprinkles as desired.