Preheat the oven to 350°F (175°C). Grease and flour two 9-inch round cake pans. In a bowl, whisk together the flour, baking powder, and salt.

In a separate large bowl, beat the butter and sugar together until light and fluffy. Add the eggs one at a time, beating well after each addition. Mix in the vanilla extract.

Gradually add the dry ingredients to the wet mixture, alternating with milk. Begin and end with the dry ingredients. Mix until just combined.

Divide the batter evenly between the prepared pans. Bake for 28-30 minutes or until a toothpick inserted into the center comes out clean. Let the cakes cool in the pans for 10 minutes before transferring to a wire rack to cool completely.

In a large bowl, beat the softened butter until creamy. Gradually add powdered sugar, beating until smooth. Add vanilla extract and heavy cream, one tablespoon at a time, until the desired consistency is reached. If using, mix in gel food coloring to match school colors.

Place one cake layer on a serving plate. Spread a generous layer of frosting on top. Add the second cake layer and frost the top and sides of the cake. Smooth out the frosting with an offset spatula.

Roll out fondant to create edible diplomas, mortarboard caps, or school mascots. Place them on the cake, adding edible pearls or other graduation-themed decorations. Use custom toppers to personalize the cake further.

Once decorated, refrigerate the cake for 20-30 minutes to set the frosting before serving. Slice and serve to celebrate the graduate’s achievements!