Ingredients:

• 3 3/4 cups (510g) all-purpose flour
• 1 1/2 teaspoons baking powder
• 1/2 teaspoon baking soda
• 1/2 teaspoon kosher salt
• 1 cup (227g) unsalted butter, softened
• 1 1/2 cups (300g) granulated sugar
• 2 large eggs
• 2 teaspoons vanilla extract
• 1 cup (227g) sour cream
• 1 cup (227g) unsalted butter, softened
• 4 cups (455g) powdered sugar
• 1 tablespoon vanilla extract
• 1/2 teaspoon kosher salt
• 1 to 2 tablespoons milk
• Food coloring, for coloring the frosting
• Sprinkles, for decorating