Make the cookies: Combine almond flour, coconut flour, and baking soda in small bowl. Whisk to combine, making sure to remove all clumps.
In another small bowl, melt coconut oil. Add peanut butter, maple syrup, and vanilla and stir well to combine.
Add wet ingredients into the dry, and mix until combined. The dough will be slightly sticky.
Measure out heaping tablespoon-sized mounds of cookie dough and roll into balls.
Divide each ball into two. Take one half, make a thumbprint in it, and dollop a scant 1/2 tsp. peanut butter inside. Make a thumbprint in the other half and carefully cover the peanut butter-filled half. Close the seam and make sure that no peanut butter is oozing out of any cracks. Carefully form into a flat circle (see photos).
Freeze for 40-50 minutes on a parchment-lined baking sheet. When there’s 10 minutes left, preheat the oven to 350 degrees F.
Bake for 9 minutes. Cool on the baking sheet for 10 minutes, then move to a cooling rack. Cookies will harden slightly as they cool.
Make the fudge sauce: Combine melted coconut oil, cocoa powder, and maple syrup in a small bowl, and mix to combine. Add additional maple syrup for extra sweetness, but know that the sauce will thin a bit. The sauce will harden in cooler temperatures. A very quick zip in the microwave will make everything nice and liquidy again.