Grasshopper Cake

Name: Grasshopper Cake
Prep time: 20 min
Cook time: 27 min
Total time: 47 min
Cuisine: American
Ingredients: 1 box (15.25 ounces) Duncan Hines Classic White Cake Mix ((see Notes below)); ¼ cup all-purpose flour; 1¼ cups water; ⅓ cup vegetable oil; 3 large egg whites ((from 3 large eggs)); ½ cup creme de menthe syrup or liqueur ((see Notes below)); 2 cups thick hot fudge topping ((see Notes below)); 8 ounces Cool Whip "Extra Creamy" ((see Notes below)); ¼ cup creme de menthe syrup or liqueur; chopped Andes Mints, (optional garnish)