Use a serrated knife to cut off the rounded tops and browned bottoms of all the cakes. Carve a crater out of the center of one cake. This will be the top layer and will hold the pie filling.
Stack the cakes and spread the red buttercream between each layer. Make sure the red buttercream isn’t poking out the sides of the cake.
Coat the entire cake (except for the inside of the crater) in a thin layer of beige buttercream. Coat the inside of the crater with the remaining red buttercream. Chill the cake in the fridge for 20 minutes.
Coat the entire surface of the cake (except for the inside of the crater) in a thick, generous layer of beige buttercream. Use a cake spatula to smooth the sides and edges.
Fill the crater with cherry pie filling. Try to minimize the amount of “sauce”, scooping mostly the pieces of cherries into the cake.
Place the remaining beige buttercream into a piping bag fitted with a medium-sized rectangular piping tip. Pipe long stripes across the cherry filling, making sure to extend the buttercream across the entire crater and only starting and stopping when the piping tip is touching the cake. Piping in a long, continuous motion, while putting consistent pressure on the piping bag, will create the cleanest lines. Pipe both horizontally and vertically, to look like a pie lattice.
Place the remaining beige buttercream into another piping bag fitted with a medium-sized star-shaped piping tip. Pipe dollops along the outside rim of the cake, creating the pie crust.
Slice and enjoy!