Stir together chopped almonds, vanilla wafer crumbs and powdered sugar in a medium bowl. Pour melted butter or margarine over crumb mixture; blend well.
Press mixture onto bottom and ½-inch up sides of a 9-inch springform pan.
Bake 8 to 10 minutes or until lightly browned. Cool completely.
Make the cheesecake filling:
Place chocolate in a small microwaveable bowl. Microwave in 30 second intervals, stirring between each until chocolate is nearly melted. Set aside to cool slightly.
Beat cream cheese, sugar, butter and vanilla in a large bowl until smooth. Add melted chocolate; beat on low speed of electric mixer.
Beat whipping cream in small bowl until stiff; fold into chocolate mixture.
Pour mixture into prepared crust. Cover and refrigerate until firm.