Bake two round cakes of the same size
Let the cakes cool completely
Cut one round cake in half
Place the two halves against the sides of the other whole cake to form a heart shape
Trim the top and bottom edges if needed to refine the heart shape
Place the cake on a serving board or plate
Apply a crumb coat of frosting
Chill the cake until the crumb coat sets
Cover the cake with a final layer of frosting
Smooth the frosting with a spatula or scraper
Decorate with sprinkles, piping, fruit, or writing as desired