Preheat oven to 350 degrees. In a bowl, combine graham cracker crumbs, sugar and butter. Into an 8-inch spring-form pan, press crust mixture. In a blender, place cream cheese and blend. Add vanilla, eggs and sour cream and blend. Add sugar and Amaretto and blend. Pour into prepared spring-form pan. Bake 60 minutes until cheesecake is firm in center. Turn off oven. Leave door slightly open and leave in oven for 1 hour. Cool in pan. Chill for several hours or overnight. Yields 8 to 10 slices.