Preheat oven to 350 degrees. Spray muffin tin with cooking spray.
In a small bowl, mix together water and chia seeds. Let sit on the side to form "eggs".
In a medium sized bowl, mash together bananas. When fully mashed, add in maple syrup, almond milk, lemon juice, and peanut butter.
Add oats, baking powder, cinnamon, sea salt, and your "chia eggs". Stir to combine. Once mixed, fold in any other mix-ins of your choice. I love adding in nuts or other fruits to change it up!
Fill each muffin cup 3/4 of the way full, pushing the frozen blueberries into the tops of the muffins and sprinkling on a few extra oats.
Bake for 25-30 minutes, or until a toothpick comes out clean.
Let cool for about 10 minutes before removing the muffins from the pan. I love eating them plain or spreading a little almond butter or ghee on top.