Heat oven to 350 degrees F. Spray a 15×10.5″ pan with non-stick spray.
Peel bananas and mash well. Stir in brown sugar, oil, milk and eggs until combined.
Add in dry ingredients and stir. Fold in 1/2 the chocolate chips.
Spread the batter into the prepared pan and sprinkle remaining chips on top. Bake 18-22 minutes, until a wooden toothpick inserted in center comes out clean.
Cool completely and cut into squares