01 - Preheat oven to 350°F. Lightly grease two small ramekins or oven-safe baking dish with cooking spray or butter.
02 - In a medium bowl, whisk together rolled oats, cocoa powder, baking powder, and salt until well blended.
03 - In a separate bowl, mash the ripe banana thoroughly. Whisk in milk, maple syrup (or honey), and vanilla extract until smooth and creamy.
04 - Pour wet ingredients into dry ingredients. Stir with a spatula until just combined, being careful not to overmix. Gently fold in chocolate chips and nuts if using.
05 - Divide batter evenly between prepared ramekins. Sprinkle additional chocolate chips on top for extra richness.
06 - Bake for 22-25 minutes until oats are set and tops appear slightly cracked. A toothpick inserted in center should come out moist but not wet.
07 - Let cool for 5 minutes before serving. Enjoy warm, optionally topped with a splash of cold milk or dollop of Greek yogurt.