Preheat oven to 325°F. Spray 3D Sandwich Pan with vegetable pan spray.
In large bowl, beat shortening and peanut butter with electric mixer until light and fluffy. Add brown sugar and granulated sugar; mix well. Add egg and vanilla, mixing until smooth. Add flour; mix well. Press dough into pan cavities, filling 2/3 full.
Bake 10-12 minutes or until lightly browned. Remove from pan to cooling grid; cool completely.
Meanwhile, tint portions of icing green and orange. To assemble cookies, spread icing on half of the cookies; sandwich with second cookie. Pipe details with icing.