Heat oven to 375°F. In large bowl, mix brown sugar, 1 cup butter, the shortening and eggs until well blended. Stir in flour, pumpkin pie spice, baking powder and salt.
On lightly floured surface, roll 1/4 of dough at a time to 1/4-inch thickness. (Keep remaining dough refrigerated until ready to roll.) Cut with 3-inch pumpkin-shaped or round cookie cutter. Place on ungreased cookie sheets.
Bake 8 to 10 minutes or until light brown. Remove from cookie sheets to cooling racks. Cool completely, about 30 minutes.
In large bowl, mix powdered sugar and 2/3 cup butter until smooth. Stir in juice concentrate. Place 1/3 cup frosting in small bowl; add green food color until desired color for stems. To remaining frosting, add 2 drops yellow food color for every 1 drop red food color for desired shade of orange. Generously frost cookies with orange frosting. Frost stems with green frosting. Make jack-o'-lantern faces with candies.