Prepare the cake: Prepare a double or triple-layer cake on a lined rectangular cardboard piece, filling it with the filling of your choice, and icing it with white buttercream. If you have a decorator’s comb, use it to recreate a ridged effect along the side of the cake.
Pipe a border around the base: Pipe a large shell border around the bottom of the cake by rotating the turntable and pulsing the white decorator’s buttercream bag.
Using the grass tip, pipe “grass” across the top with green buttercream. Make sure to pipe close together to simulate the turf on a field.