Preheat your oven to 350ºF and grease or line your muffin tin. I like to spray mine with coconut oil.
In a large bowl, mash your bananas. Get it as smooth as possible, but don't worry if there's a few lumps.
Whisk in your wet ingredients until well combined.
Add in your dry ingredients, and stir just until it's combined well.
Gently fold in your blueberries.
Divide your batter evenly among your muffin tin cups, filling about ¾ of the way.
Bake for about 20 minutes, or until a tester comes out clean.
Let your muffins cool in the tin for about two minutes, then gently remove them and place them on a cooling rack to cool completely. Store in an airtight container in the refrigerator for up to one week.