Preheat oven to 375 degrees.
Lightly spray an 8x8 baking pan with grease and line banana slices evenly on bottom.
Sprinkle half the blueberries on top, followed by 1/4 teaspoon cinnamon, and 1 tablespoon honey.
Cover pan with foil and place in oven for 15 minutes.
Meanwhile, in medium bowl, combine the oats, half the walnuts, baking powder, and remaining cinnamon.
In a separate bowl, whisk the remaining honey, milk, egg, and vanilla.
Once banana/blueberry mixture is out of oven, pour the oat mixture evenly on top of pan.
Pour milk mixture evenly over pan next and sprinkle remaining blueberries/walnuts on top.
Place pan back into oven and bake for an additional 30 minutes.
Remove from oven and enjoy!