3 – 8 oz pkgs of cream cheese
1 c sugar(divided)
1 c sour cream
2 ½ tsp vanilla (divided)
3 tbsp flour
3 eggs
¼ c cocoa
1 tbsp oil

crust:
1 c cracker crumbs
¼ c sugar
¼ c butter
¼ c cocoa
Mix and bake in a 9 inch pan at 350 F for 8-10 min. Allow this to cool a few minutes before proceeding.

Heat oven to 450 F.
Combine cheese, ¾ c of the sugar, sour cream, 2 tsp vanilla, beat well. Add flour and eggs (not all at once)beating between additions.
In small bowl, add remaining sugar, oil, vanilla, and 1 ½ c of the batter. Beat until mixed.

Add some of the white batter to the pan, then dallops of the chocolate, then cover, then final amounts of chocolate. Using a knife draw swirling motions through the batter.
Bake for 10 minutes, then reduce heat to 250 for 30 min. Turn off oven and leave the cake in for another 30 min. Loosen the sides of the pan, cool, cover and chill.