Line twenty-four 2-1/2-inch muffin cups with paper bake cups. Set aside.
Preheat oven to 350 degrees F. Prepare cake mix according to package directions, except use a mixture of the red food coloring and water to equal the amount of water called for in the package directions. Fill muffin cups and bake as directed for cupcakes. Cool cupcakes in muffin cups on wire racks for 5 minutes. Remove cupcakes from muffin cups. Cool completely on wire racks.
Spoon White Chocolate Whipped Cream into a pastry bag fitted with a large round or star tip. Push tip into the top of each cupcake and force some whipped cream inside cupcake.
Frost cupcakes with some of the white Mascarpone Frosting, pink Mascarpone Frosting, or Chocolate Buttercream. Place the remaining frostings in separate pastry bags fitted with writing tips or small star tips. Pipe messages or draw hearts onto cupcakes. Cover loosely and chill to store. Makes 24 (2-1/2-inch) cupcakes.
In a small heavy saucepan, combine white baking chocolate and 1/4 cup of the whipping cream. Cook and stir over low heat until chocolate is nearly melted. Remove from heat; stir until smooth. Cool for 15 minutes. In a large bowl, beat remaining whipping cream with an electric mixer on medium speed until soft peaks form (tips curl). Add the cooled white chocolate mixture. Beat just until stiff peaks form (tips stand straight). If desired, cover and chill for up to 24 hours.
In a very large mixing bowl beat butter with an electric mixer on medium speed until smooth. Beat in cocoa powder. Gradually add 2 cups powdered sugar, beating well. Slowly beat in 1/2 cup milk and vanilla. Gradually beat in an additional 6 cups powdered sugar. Beat in additional milk, 1 tablespoon at a time, as needed to reach spreading consistency. Makes enough to frost tops and sides of two 8- or 9-inch layers.
In a large bowl, combine mascarpone cheese and softened butter. Beat with an electric mixer on medium to high speed until smooth. Beat in vanilla. Gradually add powdered sugar, beating well. Beat in milk, 1 teaspoon at a time, to reach spreading consistency.