1 1/2 c. chocolate cookies, crushed
1/2 c. melted butter
2 (8 oz.) cream cheese
1 1/2 c. chocolate chips
1 c. sugar
2 eggs
2 tsp. cocoa
1 tsp. vanilla
1 1/2 c. sour cream

Mix crushed chocolate cookies to melted butter and put in springform pan covering sides to 1 inch from bottom.

Cream cheese and add sugar. Add eggs, one at a time. Melt chocolate chips and add to mixture. Add cocoa, vanilla and sour cream. Put in pan and bake 45 minutes at 350 degrees. Cake will be soft. Cool and chill in refrigerator for at least 3 hours.