Heat the oven and prepare the pan. Adjust oven rack to middle position and preheat oven to 350 degrees Grease an 8-inch round cake pan with nonstick cooking spray or brush lightly with coconut oil. Place an 8-inch round piece of parchment paper in the bottom of the pan.
Prepare the batter. Whisk the almond flour, coconut flour, baking powder, and salt together in a medium mixing bowl. Cut in coconut oil until no large pieces of coconut oil remain. I like to use my fingers for this. If you don’t want to use your fingers, use a pastry cutter. Remove two tablespoons of dry mixture for the streusel and place in a small mixing bowl. Set aside.
Prepare the streusel. Stir together the reserved almond flour mixture, maple sugar, and cinnamon. Sprinkle the mixture evenly over the top of the cake.
Bake the cake. Bake until a cake tester inserted into the center of the cake comes out clean, about 30 minutes.