Step 1: Prepare the Sponge Cake
Preheat oven to 350°F (175°C). Grease and line two 9-inch cake pans.
In a bowl, sift together flour, baking powder, and salt. Set aside.
In another bowl, beat butter and sugar until fluffy (about 3 minutes).
Add eggs one at a time, beating well after each. Stir in vanilla extract.
Gradually add the dry ingredients and milk, alternating, starting and ending with flour.
Divide batter evenly between pans and bake for 30-35 minutes until a toothpick comes out clean.
Cool completely before decorating.
Step 2: Make the Buttercream Frosting
Beat butter until creamy (about 2 minutes).
Slowly add powdered sugar, mixing until smooth.
Add heavy cream and vanilla extract, and beat for another 2-3 minutes until fluffy.
If making house-themed cakes, divide the frosting and color with red, green, blue, or yellow.
Step 3: Assemble & Decorate
Place one cake layer on a serving plate, spread frosting evenly, and top with the second layer.
Frost the outside smoothly, or pipe house-colored designs.
Use fondant to create decorations, such as a scar, glasses, house banners, or a spellbook.
For a golden snitch: Roll gold fondant into a ball and attach sugar-paper wings.
For a chocolate wand: Melt chocolate, pipe onto wax paper, and let harden.
Dust with edible gold dust for a magical effect!