Divide fondant in half and knead yellow coloring into one half, using a light dusting of cornstarch to prevent sticking. Working with one color at a time, roll both white and yellow fondants into thin sheets, about ⅛ inch thick. Cut out small flowers. Here is a great set of plunger cutters.
Knead scraps together to soften and make small balls; moisten with water and press a ball into the center of each flower. Dry flowers overnight on a wire rack to give them shape. Note: While working with one piece of fondant, you should always keep the other piece covered to prevent it from drying out.
Trim domed tops from cakes and place one cake on a serving platter. Color 2 cups frosting dark green and the remaining frosting light green. Cover cake layer on platter with light green frosting about ¼ inch thick, then top with second cake. Ice entire cake with light green frosting. Use extra frosting in piping bag with a #5 plain tip to create a border on the bottom edge.
Use dark green icing in a piping bag with a #10 or #12 plain tip to pipe grass points on the top of the entire cake. Top with fondant flowers.
You could of course make chocolate cake for the layers, spice cake, carrot cake...get creative. It's really the simple and fun decorations that make this the most happy cake around.Make your favorite cake from a box or use my Perfect Yellow Layer Cake recipe.