Preheat the oven to 200°C (400°F) and grease or line a standard 12-cup muffin tin.
Peel the bananas and place them into a large mixing bowl. Mash with a fork, then add the milk and olive oil. Stir to combine fully.
3 large ripe bananas, 120 ml oat milk, 60 ml olive oil
Add the flour, coconut sugar, baking powder, cinnamon, baking soda, and salt to the bowl. Use a wooden spoon or spatula to mix until just combined, being careful not to over-mix.
Add the blueberries to the batter and carefully fold in to evenly incorporate.
150 grams blueberries, plus extra for topping
Scoop the batter evenly between the cups of the prepared muffin tin. Top each with more blueberries if you'd like.
Bake for 18-22 minutes, or until golden and a wooden skewer comes out clean when inserted into the middle of a muffin.
Cool for ten minutes before removing the muffins to cool fully on a wire rack. These will keep for a day or two at room temperature but should be refrigerated or frozen for longer storage.