1. Preheat the oven to 350 degrees F. Grease an 8-inch square baking dish with the 1 tablespoon of coconut oil.
2. Make the filling: In a small bowl, mix together the coconut sugar and tapioca flour, then mash in the coconut milk and bananas, stirring to combine. Pour the filling into the prepared baking dish.
3. Make the topping: In a bowl, mix all the topping ingredients together until thoroughly combined yet still chunky, and spread it evenly over the filling. Bake, uncovered, for about 30 minutes, or until the top is browned and crispy (NOTE: After 30 minutes of baking, the inside of the crisp will be soft while the outside will be drier and harder. I love gooier desserts! It is safe to eat this way, as this recipe contains no egg or any other type of animal products). Let cool on a wire rack for at least 10 minutes before serving with vanilla coconut ice cream, if desired.