01 - Preheat oven to 350°F. Lightly grease two small ramekins or an oven-safe baking dish with cooking spray or a small amount of oil.
02 - In a medium bowl, mix together the rolled oats, cocoa powder, baking powder, and salt until well combined.
03 - In a separate bowl, whisk together the mashed banana, milk, maple syrup (or honey), and vanilla extract until smooth and fully incorporated.
04 - Pour the wet ingredients into the dry ingredients. Stir until evenly combined and no dry streaks remain. Gently fold in the chocolate chips and nuts if using.
05 - Divide the batter evenly between the prepared ramekins. Sprinkle extra chocolate chips on top of each portion for a melty finish.
06 - Bake for 22 to 25 minutes until the oats are set and the tops appear slightly cracked. A toothpick inserted in the center should come out mostly clean.
07 - Let the baked oats cool for 5 minutes before serving. Enjoy warm, optionally drizzled with additional milk or topped with a dollop of yogurt.