Bake and cool leaf whoopie pies according to package instructions. You will need two leaves for each sandwich.
Cut leaves flat. Prepare filling and spread on half the leaves; sandwich together with second leaf. Roll edge in sprinkles.
Prepare icing. Tint portions red, yellow, orange and brown. Use tip 3 and assorted shades of icing to pipe veins on leaves.
Roll fondant into logs: 23 in. long x 3/8 in. wide; 6 3/4 in. long x 3/8 in. wide; 7 in. long x 3/8 in. wide; and 8 1/2 in. long by 3/8 in. wide. Position logs on plate or cake board. Position whoopie pies.