Position oven rack in middle of oven; spray cookie sheets with nonstick cooking spray.
In a big bowl place half of the cake mix along with the oil, eggs, and pumpkin pie spice.
Blend with an electric mixer set on medium-high speed 1-2 minutes, until blended and smooth.
Stir in the remaining cake mix, grated carrot, raisins, and drained pineapple with a wooden spoon until all dry ingredients are moistened (dough will be stiff).
Drop dough by teaspoonfuls, 2 inches apart, onto prepared cookie sheets.
If desired, sprinkle cookie tops with nuts; gently press nuts into dough.
Bake 11-14 minutes or until set at edges and just barely set at center when lightly touched.
Cool 1 minute on sheets; transfer cookies to wire racks with metal spatula and cool completely.
Make frosting: in a bowl, beat the cream cheese, softened butter, and vanilla extract with an electric mixer on medium speed until blended and smooth.
Gradually add the powdered sugar, beating until incorporated and smooth.