Prepare the cake: Prepare a quadruple layer cake on a lined rectangular cardboard piece, filling it with the filling of your choice.
Using a serrated knife, cut the ends of the sheet cake to make a point. Keep carving the sides of the cake to mimic the shape of a football. (TIP: The cake should be chilled to prevent the frosting from slipping.)
Once carved, lightly brush off any crumbs.
Ice the cake in a thin layer of buttercream. (TIP: We used chocolate buttercream, make by combining equal parts vanilla buttercream and chocolate fudge frosting.)
Lift cake onto a rack, and gently ladle melted ganache over the top of the cake.
Let covered cake sit for 15 minutes, or until the ganache sets.
Using a number 7 tip, a horizontal line in the center of the cake, and pipe lines crossing over it to resemble laces.
Using a leaf tip, pipe two vertical lines on each side of the cake to represent football laces.
Using a grass tip, gently pipe grass along the seam of the cake.