In a bowl, combine the flour, brown sugar, cinnamon, baking powder, baking soda and salt. In a small bowl, beat the margarine, orange juice and egg on medium speed for 1 minute (mixture will not be smooth). Stir into dry ingredients just until blended. Fold in carrots and raisins.
Coat muffin cups with cooking spray or use paper liners; fill half full with batter. Bake at 350° for 20-25 minutes or until a toothpick comes out clean. Cool for 5 minutes before removing from pan to a wire rack.