Place the oats in the bottom of a blender. Pulse a few times to grind and break up, then add the mashed banana, Greek yogurt, milk, eggs, honey, baking powder, cinnamon, salt, powered pb, and nutmeg.
Blend on high speed, stopping to stir a few times as needed, until the batter is very smooth and well combined, about 2 minutes. Let sit 10 minutes.
Heat a griddle over medium heat. Spray lightly with olive oil or melt a little butter in the pan. Pour ¼ cup of batter onto the hot griddle bake until the edges look dry (bubbles may not form on top). Flip and continue to cook for 1 to 2 additional minutes. Repeat with the remaining batter, adding a little more oil to the pan between batches as needed.
You can freeze these in a single layer on a lined pan - once frozen then transfer to a ziplock bag to keep in freezer.
Otherwise they will stay fresh in the fridge for 2 days. Just reheat in oven or toaster oven when ready to eat.