1. Baking the Cake Layers

1. Preheat oven to 350°F (175°C). Grease and line four 8-inch round cake pans.
2. Prepare cake batter according to package instructions. Divide batter into four bowls.
3. Tint each bowl of batter with a different food coloring: red (Gryffindor), yellow (Hufflepuff), blue (Ravenclaw), and green (Slytherin).
4. Pour each colored batter into its own cake pan and bake for 20-25 minutes, or until a toothpick comes out clean.
5. Cool layers in the pans for 10 minutes, then transfer to a wire rack to cool completely.

2. Making the Buttercream Frosting

1. Beat softened butter until smooth and creamy.
2. Gradually add powdered sugar, 1 cup at a time, mixing well after each addition.
3. Stir in vanilla extract and heavy cream until the frosting reaches a smooth, spreadable consistency.
4. Optionally, tint the frosting with food coloring for extra detail.

3. Assembling the Cake

1. Trim the tops of the cooled cake layers to ensure they’re level.
2. Place the first layer (Gryffindor) on a cake stand or plate. Spread a thin layer of frosting over the top.
3. Continue stacking the layers in the following order: Gryffindor, Hufflepuff, Ravenclaw, and Slytherin.
4. Apply a crumb coat to seal in any loose crumbs, then chill the cake for 10 minutes to set.

4. Decorating the Cake

1. Frost the entire cake with a smooth layer of buttercream frosting.
2. Lightly dust with edible gold dust or sprinkles for a magical touch.
3. Add themed decorations like fondant lightning bolts, the Hogwarts crest, or house symbols.
4. Optional: Drizzle with chocolate ganache for added flair.