Prepare the white cake mix according to package instructions, adding milk, vegetable oil, egg whites, cotton candy extract, clear vanilla extract, and gel food coloring as desired.

Bake the cake in accordance with the package instructions.

Allow the cake to cool completely.

In a bowl, beat unsalted butter until creamy. Gradually add powdered sugar and heavy cream, mixing until smooth.

Add cotton candy extract and vanilla extract to the buttercream and mix well.

Use gel food coloring to tint the buttercream as desired.

Assemble the cake by layering the cooled cakes with buttercream in between.

Decorate the cake with cotton candy, sprinkles, edible glitter, sugar pearls, and melted white chocolate.