Preheat your oven to 350°F (175°C). Line a 12-cup muffin tin with paper liners or grease well.
In a large bowl, whisk together the oats, flour, baking powder, cinnamon, and salt until well combined.
In another bowl, mix the mashed bananas, honey, oil, and vanilla extract until smooth.
Pour the wet mixture into the dry ingredients and gently stir until just combined. Fold in the blueberries.
Fill the muffin cups about two-thirds full with the batter.
Bake for 18 minutes, or until a toothpick inserted into the center comes out clean.
Allow the muffins to cool in the pan for 5 minutes before transferring to a wire rack to cool completely.
Notes
For a nutty twist, consider adding half a cup of chopped walnuts or almonds to the batter. Additionally, try substituting maple syrup for honey for a different sweetness profile.