Preheat oven to 350 degrees F. Slice bananas into ½ inch slices and place into a medium baking dish. Top with butter and sprinkle with brown sugar. Bake for 30 minutes, they will be bubbly and golden brown. Remove from oven and let sit until it cools. Mix bananas with the softened cream cheese and sugar until combined well.
Prepare brownie mix according to the directions on the box. Line a 10x10 inch baking dish (makes for a thicker brownie with this size of dish), with tin foil that’s been sprayed with cooking spray.
Pour brownie batter into prepared dish. Drop banana cream mixture by the spoonfuls evenly over brownie batter. Gently run a knife through the banana and brownie mix, and swirl but do not scrap the bottom of the pan or you will tear the foil.
Bake for 40-45 minutes in a 350 degree oven or until toothpick comes out clean from middle of brownies. Let cool completely, then pull out of pan with foil edges and refrigerate.
When completely cooled melt white chocolate chips and peanut butter in the microwave and pour over the top of the brownie let cool completely and cut.