Preheat oven to 350 degrees F. Spray a 9x13 baking dish with nonstick cooking spray.
In a medium size bowl, mix together the flour, oats, peanut powder, hemp seeds, baking powder and cinnamon.
In another medium size bowl, whisk together the bananas, eggs, brown sugar, butter and milk until well combined. Add the wet ingredients to the dry ingredients and stir until combined. Pour mixture into prepared baking dish and spread evenly.
Put the blueberries and ½ tablespoon of sugar in a microwave safe bowl. Microwave in 1 minute intervals, stirring at the end of each one, until blueberries being to release their liquids and slightly smashed. Spread blueberries evenly over mixture in pan.
In a small bowl, mix together the topping ingredients: oats, flour, cinnamon and brown sugar. Cut the butter in with 2 knives, or use your hands to crumble and distribute butter throughout mixture so it resembles coarse meal. Sprinkle evenly over the blueberries.
Bake in the oven for 30 minutes or until lightly browned. Allow to cool in pan completely before cutting and serving.