1-Preheat oven and prepare pans: Creating your birthday sprinkles cake starts with simple preparation that anyone can follow, even if you’re new to baking. Begin by preheating your oven to 350°F (175°C) and greasing two 9-inch round cake pans for even baking. This step sets the stage for a smooth process that leads to a fluffy, colorful result.

2-Mix dry ingredients: In a large bowl, whisk together the dry ingredients: 3 and 3/4 cups cake flour, 1 teaspoon baking powder, 1 teaspoon baking soda, and 1 teaspoon salt. This mixture forms the foundation of your cake, ensuring it rises perfectly and holds its shape.

3-Cream butter and sugar: In another bowl, cream 1 and 1/4 cups softened unsalted butter with 2 cups granulated sugar until it’s light and fluffy, which usually takes about 3-5 minutes with a mixer.

Next, add 1/3 cup vegetable oil to the butter mixture for extra moisture, then beat in 4 large eggs and 2 large egg whites one at a time, followed by 3 teaspoons pure vanilla extract. Alternate adding the dry ingredients with 1 and 1/2 cups buttermilk, starting and ending with the flour mix, to create a smooth batter. Gently fold in 3/4 cup rainbow sprinkles to keep those colors vibrant. Pour the batter into your prepared pans, smooth the tops, and bake for 25-30 minutes or until a toothpick comes out clean.

After baking, let the cakes cool in the pans for 10 minutes, then transfer to a wire rack. Once fully cooled, you can frost with the vanilla buttercream made from 1 and 1/2 cups softened unsalted butter, 5 and 1/2 cups confectioners sugar, 1/3 cup heavy cream, 3 teaspoons pure vanilla extract, and 1/8 teaspoon salt. For an external resource on frosting techniques, see our baking essentials guide. Finish with optional additional sprinkles for a festive look, and your cake is ready to serve.