1 c. flour
1/4 c. sugar
1/4 tsp. salt
6 tbsp. butter, cold
3 tbsp. cocoa
1/2 tsp. vanilla
2 tbsp. ice water
1 egg yolk

FILLING:

5 (8 oz.) cream cheese
1 1/2 c. sugar
1/2 tsp. salt
2 tsp. vanilla
5 eggs
1 c. sour cream
4 oz. semi-sweet chocolate, melted
3 very ripe bananas
1 tbsp. lemon juice

PASTRY: Stir flour, sugar and salt. Cut in butter. Add cocoa and other ingredients. Gather together and flatten into a disc. Refrigerate. Butter sides and bottom of spring form pan. Press half of dough onto bottom. Bake at 400 degrees for 6 minutes. Attach sides of pan and pat remaining pastry 3/4 up sides.

FILLING: Beat cream cheese and sugar for 3 minutes. Add salt and vanilla. Add eggs, 1 at a time. Mix in sour cream. Remove 1 1/4 cup cheese mixture. Stir in chocolate. Mash bananas (1 1/2 cups) and add with lemon juice. Add to non-chocolate mix. Pour 2/3 into pan. Spoon chocolate mix in a ring. Cover with remaining banana mix.

Bake on baking sheet at 425 degrees for 15 minutes, then 225 degrees for 60 to 65 minutes. Turn off oven and let cool for at least 2 hours. Finish cooling at room temperature, then refrigerate.