Mix cream cheese and vanilla pudding until thoroughly incorporated. Add milk and eggs and mix until combined. Stir in banana extract.
To make brownies: Mix together both sugars, butter, vanilla extract and eggs. Add flour, salt, baking powder. Mix together to form a thick dough. Line a 9×13 glass casserole pan with parchment paper, leaving enough overhang to lift the brownies out of the pan. Drop the brownie mix in and spread evenly in the pan. Pour filling on top and spread evenly over the dough. Lay vanilla wafers on top in a 4 x 6 pattern. Bake at 350° for 45 minutes or until the top is golden brown. Remove from oven and let cool completely before cutting into squares.