1 cup vanilla wafer crumbs
1/2 cup chopped pecans
3 tablespoons granulated sugar
1/4 cup margarine, melted
16 ounces cream cheese, softened
1/2 cup packed brown sugar
2 eggs
6 ounces semisweet chocolate chips, melted 
3 tablespoons almond-flavored liqueur
2 cups sour cream
2 tablespoons granulated sugar

Combine crumbs, pecans, the 3 tablespoons granulated sugar and margarine; press onto bottom of a 9-inch springform pan. bake at 325 degrees F for 10 minutes.

Combine cream cheese and brown sugar, mixing at medium speed of electric mixer until well blended. Add eggs, one at a time, mixing well after each addition. Blend in chocolate and liqueur; pour over crust. Bake at 325 degrees F for 35 minutes.

Increase oven temperature to 425 degrees F.

Combine sour cream and the 2 tablespoons granulated sugar. Carefully spread over cheesecake. Bake at 425 degrees F for 10 minutes.

Loosen cake from rim of pan. Cool before removing rim of pan. Chill.

Variation
Substitute 2 tablespoons milk and 1/4 teaspoon almond extract for almond flavored liqueur.