Preheat oven to 180 C. Prepare muffin tray and paper case and grease with oil spray (I use silicone mold)

Peel and mash the bananas

In a large bowl add mashed bananas, egg, melted coconut oil/butter, and vanilla, and whisk to combine. Set aside.

In another bowl, stir flour, baking powder, baking soda, and sugar.

Make a well in the center of the flour, fold in liquid ingredients and stir with a silicone spatula halfway, then fold in berries and keep stirring a few more times to incorporate. Don't over-mix the batter, stir until no more lump of flour can be seen not more. If you over-stir the batter, the muffins come out dense or sometimes gummy.

The batter should be thick but not overly dry, if dry add 1-2 tablespoons extra milk or water.

Fill the muffin cases up to 3/4 level.

Bake the muffins on the center rack of the oven at 350°F (180°C) until a pick inserted in the center of the muffin comes out clean – about 25-35 minutes.