Preheat the oven to 425˚F. Grease an 8x8-inch baking dish generously with coconut oil.
Bring 2 cups of water to a boil.
In a heatproof bowl combine the oats, chia seeds, ground flax seeds, cinnamon, cardamom and salt. Stir to combine. Plop in 2 tablespoons of coconut oil. Pour the boiling water over the mixture and stir well. Cover with plastic wrap and let sit 5-10 minutes.
Meanwhile, in a separate bowl, mash the bananas using a fork until mostly smooth. Stir in the maple syrup.
Pour the banana mixture over the oats (which will be quite clumpy at this point) and stir well to combine. Fold in the berries.
Transfer the mixture to the greased baking dish and bake 30 minutes, or until golden on top and around the edges. Let cool 5-10 minutes (the longer it cools, the easier it will be to cut). Cut into bars and serve warm or at room temperature.