If using instant pudding, cook according to package instructions. Bring water to boil, stir in quick-cooking oats and cook until thickened, about 1-2 minutes. For thinner oatmeal, add just a bit more water. Divide oatmeal amongst 4 oven-proof bowls. Place oven rack near top and turn on broiler. Top each bowl with vanilla pudding and banana slices. Sprinkle brown sugar and cinnamon on top. Place in broiler until sugar melts and begins to bubble.
