Preheat oven to 350 degrees.
Melt butter and allow it to slightly cool.
Mix rolled oats, cinnamon, baking powder, and salt in large bowl.
Beat milk and eggs together in separate bowl. Add butter and whisk well.
Pour wet ingredients into dry ingredient bowl and fold in. Add blueberries and mix gently.
Lay sliced bananas on the bottom of a 13x9 pan. Pour blueberry mixture on top and spread evenly.
Bake at 350 degrees for 35-40 or until bubbly. Allow to sit at room temperature for 10 minutes before serving.