Preheat the oven to 350*F/ 175*C.
Start by making the flax egg- combine the ground flax with water and set aside for about five minutes.
Then, in a large bowl, mash the bananas.
To the bowl with mashed bananas, add the oats, oat flour, flax egg, nut butter, maple syrup, milk, baking powder, vanilla, cinnamon, and salt.
Combine the ingredients well and then fold in your blueberries.
Line a muffin pan with muffin liners.
Fill each muffin cup almost to the top (these will not rise much).
You can top them with more blueberries and some almond slices.
Bake in the oven for 35-40 minutes.