1 c. vanilla wafer crumbs
1/4 c. melted butter
2 (8 oz.) pkg. cream cheese, softened
3/4 c. sugar
1 (8 oz.) carton sour cream, divided
4 eggs
1 tsp. vanilla
1 (6 oz.) pkg. mini chocolate chips
1/2 c. sugar
1 1/2 tsp. lemon juice
1 1/2 tsp. vanilla

Combine wafer crumbs and butter. Mix well and press into bottom of 9 inch springform pan. Beat cream cheese until fluffy, gradually adding 3/4 cup sugar and 1/2 cup sour cream. Add eggs one at a time beating well. Stir in 1 teaspoon vanilla and chocolate chips. Spoon on top of crust. Bake at 325 degrees for 1 hour. Cool 20 minutes. Combine remaining sour cream, sugar, lemon juice, and vanilla. Mix well and spread over top. Bake at 475 degrees for 5 minutes. Cool and refrigerate 8 hours. Remove from pan.