1Preheat oven to 350 degrees F (175 degrees C). Stir together the flour, baking powder, and salt; set aside.
2Cream together 1 cup margarine and sugar until light and fluffy. Add the eggs one at a time while continuing to beat until incorporated. Continue to beat in the mashed carrot, coconut, and flour mixture until all the ingredients are well moistened. Drop by spoonfuls onto ungreased baking sheets 2 inches apart.
3Bake in the preheated oven until the cookies slightly flatten and are golden around the edges, about 8 minutes. Remove from the oven, and allow to cool on the pan for 5 minutes. Remove to a wire rack, and cool completely.
4To make the orange-butter frosting, cream together 1/3 cup margarine with confectioners' sugar, orange zest, and orange juice until light and fluffy. Ice the cookies with the frosting once cool.