Preheat the oven to 350 °F (175 °C) and get out an 8"x8" (20cmx20cm) baking dish.

In a medium mixing bowl, stir together the almond flour, coconut flour and cinnamon. Then add the coconut oil, maple syrup and salt and mix until combined.

Pulse the pecans or walnuts in a food processor a few times until they're in small pieces (about 1/8" in size). You can also chop them by hand but the food processor takes a lot less time. Stir the nuts into the topping mixture.

In another medium mixing bowl, stir together the filling ingredients except for the blueberries. When well combined, gently stir in the blueberries and coat in the liquid mixture.

Pour the blueberry mixture in the baking dish.

Distribute the topping evenly over the blueberries.

Bake for 35-40 minutes or until the topping is firm and the blueberries are bubbling. The topping will crisp up much slower than a traditional crisp, but don't worry as it will crisp up towards the very end of the baking time. Cover the crisp with foil if the topping starts to brown too early.

Let cool for 10 minutes and serve. If not serving immediately, once cool, loosely cover with a piece of plastic wrap (so the topping doesn't go soft). If storing overnight, properly cover the crisp with plastic wrap. Do note that the topping gets soft on the second day. Serve with vanilla sauce or ice cream.