Start by heating your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans, or line them with parchment paper to ensure the cake comes out easily after baking.

In a separate bowl, whisk together the flour, baking powder, and salt. This helps to evenly distribute the dry ingredients and ensures a consistent texture throughout the cake.

In a large mixing bowl, beat the softened butter and sugar together until the mixture becomes light and fluffy. This process usually takes about 3-4 minutes using a hand mixer or stand mixer. The fluffier the butter and sugar, the lighter and more delicate your cake will be!

Incorporate the eggs one by one, mixing each in completely before adding the next. Once all the eggs are added, pour in the vanilla extract and stir until the batter becomes smooth and well-blended.

Gradually add the dry ingredients to the butter mixture, alternating with the milk. Start and finish with the dry mixture, mixing gently until combined. Be careful not to overwork the batter to keep it tender.

Divide the batter evenly between two bowls. Add your food coloring (either blue or pink) to one bowl and stir carefully until you achieve a vibrant hue. The colored batter will be the secret surprise inside the cake!

Begin by spooning the uncolored batter into the cake pans. Then, drop the colored batter into the center of the uncolored batter in each pan. As you add the colored batter, it will naturally spread outwards, creating a hidden surprise inside the cake once it’s cut.

Place the cake pans in the preheated oven and bake for 30-35 minutes. Check the cakes by inserting a toothpick into the center—if it comes out clean, the cakes are ready!

Allow the cakes to cool in their pans for 10 minutes, then transfer them to a wire rack to cool completely. Cooling them completely is key to preventing the cake layers from breaking apart when you start frosting.

After the cakes have cooled, place one layer on your cake stand or serving platter. Spread a thick layer of frosting over the top of the first layer, then gently place the second cake layer on top. Continue frosting the entire cake and feel free to add extra decorations like sprinkles or edible glitter for a magical touch!