Mix the almond flour, coconut flour, cocoa powder, baking powder, baking soda and salt in a mixing bowl and set aside.
Using an electric mixer, cream the butter and monkfruit sweetener until well blended. Add the egg, sour cream and vanilla extract.
Keep the mixer on low and add the flour mixture until well combined. Wrap the dough ball in plastic wrap, then chill overnight.
Scoop the dough using a 1-inch cookie scoop and bake on a silicone lined baking sheet at 350 degrees F for 9-11 minutes. Remove the cookies from the oven while they are still slightly soft in the center (they will finish cooking as they cool).
Allow the cookies to cool on the baking sheet for 10 minutes, then transfer to a wire baking rack to cool completely.
While cookies are cooling, melt 1-2 tablespoons coconut oil in a small saucepan over low heat. Add in 1/2 cup of sugar-free chocolate chips and stir until melted smooth.
Dip cooled cookies into the chocolate to coat. Optional: sprinkle with chocolate shavings, sprinkles, or toppings of your choice.