Preheat oven to 350°. Spray baking pan with vegetable pan spray.
Bake 40-45 minutes or until toothpick inserted in center comes out clean. Cool in pan 10 minutes. Remove from pan and cool completely.
Cut cake into 2 layers. Combine 1/2 cup icing with ice cream topping; spread between cake layers. Lightly ice cake with remaining icing.
To Decorate: Roll out and completely cover cake with white fondant. Smooth with palm of hand or Easy Glide Fondant Smoother.
Use colored fondants to create leaves: roll out fondant 1/8 inch thick, either directly from the package, combining colors to create new colors or marbling 2 or more colors. Using the largest leaf cutter, cut out 3 or 4 leaves at a time in various colors.
Position on cake, attaching with brush dipped in water; smooth edges with fingers, to cover entire cake.
For border, roll out colored fondant 1/8 inch thick. Using smallest leaf cutter, cut out leaves in various colors.
Attach to bottom of cake using brush dipped in water.
Create leaf "veins" using thin ropes of colored fondant or painting them on using Brush-On Color?.