Preheat your oven to 190°C (375°F). Grease a 12-cup muffin pan or line it with muffin liners.
In a large mixing bowl, mash the ripe bananas until smooth.
Add the oat flour, oats, almond flour, coconut sugar, baking powder, and salt to the bowl. Stir until well combined.
Pour in the almond milk and vanilla extract. Gently mix until you achieve a thick, pourable batter.
Fold in any optional mix-ins like chocolate chips or nuts if desired.
Divide the batter evenly among the muffin cups, filling each about three-quarters full.
Bake for 18-22 minutes, or until a toothpick inserted into the center of a muffin comes out clean.
Let the muffins cool in the pan for a few minutes, then transfer them to a wire rack to cool completely. Serve warm or store for later.