Preheat the oven to 325 degrees F and lightly mist an 8x8 pan with non-stick spray.
Place the flours, cocoa, sugar, baking soda, baking powder, and salt in a large mixing bowl and stir to combine.
Add the coconut oil, and stir on low speed until the mixture resembles damp sand.
Add the eggs, one at a time, and beat until incorporated.
Scrape the bottom and sides of the bowl with a silicone spatula, and add the Greek yogurt, applesauce, and vanilla extract.
Mix on low speed for about a minute, to aerate the batter and develop the structure of the cake.
Pour in the maple syrup and stir just until combined.
Bake for 30 minutes or until a tester comes out clean or with a few moist crumbs.
Sprinkle mini chocolate chips on the warm cake, for garnish.
Allow to cool completely, then dust with powdered sugar.