Preheat oven to 350°F and line a muffin pan.
In a food processor or high speed blender, blend 1 cup of the oats into an oat flour and put them in a large bowl. Add the remaining oats, chia seeds, flax seed, cinnamon, baking powder, and salt and whisk to combine.
In a small bowl, add the milk, maple syrup, nut butter, banana, and vanilla and whisk until smooth.
Slowly stir the wet mixture into the dry mixture. Gently fold in the blueberries.
Add to lined muffin pan and bake for 35-38 minutes or until a toothpick inserted into the center comes out clean.