Preheat oven to 350 degrees.
In a medium bowl combine oats, flaxseed meal, cinnamon, nutmeg, baking powder, and salt. Set aside.
In a separate bowl, whisk eggs together with maple syrup, oil, mashed banana, milk, and vanilla until combined.
Pour the dry ingredients into the wet ingredients. Mix well.
Stir in peanut butter and chocolate chips. Mix well, making sure peanut butter is incorporated into the batter.
Line a muffin pan with baking cups or thoroughly spray muffin pan with non-stick cooking spray.
Divide the oatmeal mixture among muffins cups, filling each cup to the top.
Bake for 25-30 minutes or until the tops are slightly brown and a toothpick inserted comes out clean.
Cool on a wire rack.