For crust: In a bowl, combine crushed graham crackers and melted butter or margarine. Press evenly on bottom and 2 inches up sides of a 10-inch springform pan. Set aside.

For filling: In a large mixing bowl, beat cream cheese, the 1-1/4 cups sugar, the creme de menthe, and vanilla with an electric mixer on medium speed for 2 minutes. Add eggs all at once, beating on low speed until just combined. Pour mixture into prepared crust. Place on a shallow baking pan in oven.

Bake in a 325 degree F oven for 1 hour and 10 minutes or until the filling is just set.

Stir together the sour cream and the 1/3 cup sugar. Carefully spread over cheesecake. Bake for 10 minutes more. Cool for 15 minutes. Loosen the edges. Cool for 30 minutes. Remove the sides of pan. Cool completely.

In a small saucepan, heat milk-chocolate pieces and shortening over low heat until melted. Remove from heat. Cool. Spread the melted chocolate over the top of the cheesecake.

After 5 minutes, score the chocolate layer into 9 to 16 pieces so it will be easier to cut later. Cover and chill the cheesecake until it's time to serve. Makes 9 to 16 servings.

Instead of spreading the melted-chocolate mixture on top of the cheesecake, you can pour it in a mound on a foil-lined baking sheet. Spread into a 7-inch circle. Cool for 5 minutes. Use a cake comb to make swirls on the chocolate, if you like. Cool until chocolate holds a cut edge. Cut into wedges. Place on top of the cheesecake.