2 c. yellow cake mix
1 egg
1/4 c. oil

Mix and pat into spring form pan. Bake 15 minutes at 350 degrees.

CHEESECAKE:

1 c. chocolate chips
1/2 c. sugar
2 (8 oz.) pkg. cream cheese, softened
3/4 c. sugar
1/2 c. sour cream
1 tsp. vanilla
4 eggs

Combine over hot, not boiling, water: chocolate chips and 1/2 cup sugar. Can be done in the microwave. Heat until mixture is smooth and chips are melted. Set aside. In large bowl, beat cream cheese until light and creamy. Gradually beat in 3/4 cup sugar. Mix in sour cream and vanilla. Add eggs, one at a time beating well after each one. Pour half of mixture into slightly cooled spring form pan. Stir chocolate mixture into remaining cream cheese batter.

When smooth, pour about 4-5 big spots into spring form pan. Swirl batter with a knife. Bake at 325 degrees for 50 minutes or until only a 2-3 inch circle in center will shake. Cool at room temperature. Refrigerate.