Preheat oven at 350 °F and grease a 8 or 9 inch springform pan.
Blend ripe banana and cream cheese until smooth. Set aside for later.
Cream butter and sugar together until smooth. Add eggs, vanilla, and sour cream and blend again. Beat in the baking powder, soda, and flour until batter is smooth and no lumps are visible. Fold in chocolate chips.
Pour ¾ of the chocolate chip batter in the bottom of the greased springform pan.
Spread the banana cream cheese mixture on top then top the cake with the remaining chocolate chip batter evenly.
Bake for 50 minutes or until a toothpick comes out clean.
Remove from oven and let cook. Sprinkle with powder sugar if preferred.