1/3 c. butter, melted
1 1/4 c. graham cracker crumbs
1/4 c. sugar
3 (8 oz.) pkg. cream cheese, softened
1 can condensed milk
1 (12 oz.) pkg. semi-sweet chocolate chips
4 eggs
2 tsp. vanilla

Preheat oven to 325°F. Combine butter, crumbs and sugar. Pat firmly on bottom of 9-inch spring-form pan. In large mixer bowl, beat cream cheese until fluffy. Add condensed milk; beat until smooth. Add remaining ingredients. Mix well. Pour into pan.

Bake 1 hour and 5 minutes or until top is set. Cool at room temperature. Chill and then remove sides of pan.