Pre-heat oven to 180c (fan) / 350F / Gas 4 and grease a mini muffin tray (or standard muffin tray).
In a large mixing bowl add the mashed bananas and oats, and stir until combined.
Add the milk, egg & vanilla and stir until fully combined.
Add the berries and stir until evenly distributed throughout. Break up some of the bigger berries as you stir them through the mixture.
Divide the mixture between the 24-cup sections (mini tray).
Bake until cooked through (a cocktail stick should come out clean) approx. 18 minutes if using a mini muffin tray or approx. 25 min if using a standard tray.
