1-Getting started with this yellow sheet cake begins with preheating your oven, a simple step that sets the stage for success. Preheat to 350°F (177°C) and prepare your pan by greasing and lightly flouring a half sheet pan (12×17 inches) or quarter sheet pan (9×13 inches). This ensures your cake releases easily after baking.

2-Next, mix the dry ingredients in a large bowl. Whisk together 2 and 1/4 cups (266g) cake flour, 2 and 1/2 teaspoons baking powder, 1/4 teaspoon baking soda, and 1/2 teaspoon salt. This step helps distribute the leavening agents evenly for a consistent rise.

3-In a separate bowl, beat 1 cup (16 tablespoons; 226g) unsalted butter, softened, and 1 and 1/2 cups (300g) granulated sugar on high speed for about 3 minutes until creamy. Don’t forget to scrape the sides of the bowl as needed to get everything well mixed.

4-Then, add 2 large eggs, at room temperature, and 2 teaspoons pure vanilla extract, beating until combined. Follow that by mixing in 1/2 cup (120g) sour cream, at room temperature, for added tenderness. For a deeper dive into baking techniques, check out this easy dump cake recipe on our site for more tips on simple preparations.

5-Now, combine the wet and dry mixtures. Add half of the dry ingredients and half of 1 cup (240ml) whole milk, at room temperature, beating on low speed until just mixed. Then add the rest of the dry ingredients and milk, mixing carefully to avoid overworking the batter. Pour it into your prepared pan and smooth it out evenly.

6-Bake the cake for 20 to 22 minutes if using a quarter sheet pan, or 36 to 40 minutes for a half sheet pan. Remember to rotate the pan once or twice for even cooking. You’ll know it’s done when a toothpick inserted in the center comes out clean.

7-Let the cake cool in the pan on a wire rack before moving on. For the frosting, beat 1 cup (16 tablespoons; 226g) unsalted butter until creamy, then sift in 4 and 1/2 cups (540g) confectioners’ sugar and 3/4 cup (62g) natural unsweetened cocoa powder. Blend on low speed before adding 1/2 cup (120ml) whole milk, 1 tablespoon light corn syrup (if using), 1 and 1/2 teaspoons pure vanilla extract, and 1/8 teaspoon salt. Beat on medium-high for 2 minutes until smooth.

8-Spread the frosting over the cooled cake and add rainbow sprinkles if you like. This whole process, from prep to finish, takes about 2 hours, giving you a tasty treat that’s worth the effort.