2 cups all-purpose flour
½ cup cocoa powder
1 ½ tsp baking powder
1 cup sugar
½ cup oil or melted butter
1 cup milk
1 tsp vanilla extract
½ cup melted Bournville Dark Chocolate
Gel food coloring
1 ½ cups heavy cream
½ cup powdered sugar
¼ cup melted Bournville Dark Chocolate
Mix flour, cocoa powder, baking powder, and sugar. Add oil, milk, vanilla, and melted chocolate, and whisk until a smooth batter forms.
Divide batter into six portions and color each with a different color for the rainbow. Bake at 175°C for 15-20 minutes.
Whip heavy cream, powdered sugar, and melted chocolate until fluffy and frothy. Stack the layers in rainbow color order with frosting in between. Coat the entire cake with remaining frosting.
Mix melted chocolate with warm milk, drizzle over the cake and let drip from the edges. Decorate the cake with sprinkles then slice it to serve.