Start by mashing your ripe banana in a bowl until smooth. I like a few small chunks left for texture, but you can mash it completely if you prefer creamier oats.
Add peanut butter, milk, honey (if using), and vanilla extract to the mashed banana. Stir everything together until smooth and creamy, making sure the peanut butter is fully incorporated.
Stir in oats, chia seeds, and a pinch of salt. Make sure the oats are evenly coated with the wet mixture for consistent flavor in every bite.
Transfer the mixture to a mason jar or airtight container and refrigerate for at least 6 hours, or overnight. This allows the oats to soak and become creamy and soft.
The next morning, give the oats a quick stir. If needed, add a splash of milk to loosen the mixture. Top with banana slices, a drizzle of peanut butter, or your favorite nuts for extra flavor and crunch.