Preheat oven to 375 degrees. Lightly grease a 2-quart baking dish.
In a medium bowl, combine the rolled oats, baking powder, cinnamon, half of the coconut and salt; stir with a fork to combine.
In a liquid measuring cup, combine the maple syrup, milk, egg, butter, and vanilla.
Spread the sliced bananas in a single layer over the bottom of the baking dish; top with half of the berries. Sprinkle the dry oat mixture over the fruit in an even layer. Pour the liquid ingredients evenly over the oats. Sprinkle the remaining coconut and berries over the top.
Bake for 35-40 minutes, until the top is browned and the oats have set. Let cool 10 minutes before serving.