Preheat the oven to 350F and spray muffin tin with non-stick spray.
Mix oats, salt, and baking powder in a large bowl.
In a medium-sized bowl, mix mashed banana, peanut butter, and honey. Stir in egg.
Pour wet ingredients into the oat mixture, then add milk.
Stir until everything is well combined.
Scoop the mixture into the prepared muffin tin and bake for 25 minutes.
Once cooled, topped with additional banana slices and drizzle with peanut butter.
Store in the fridge or freezer for a later date.