Preheat oven to 425 degrees F. Line a muffin tin with liners or spray with cooking spray.
To make the crumble. Add the brown sugar, pecans, coconut, 2 tablespoons quinoa, cinnamon and the flour to a bowl. Add the butter and using your fingers, a fork, or a pastry cutter, work the butter into the dry ingredients until large heavy crumbs are formed. Set aside
In a large mixing bowl whisk together the flour, quinoa, baking powder, baking soda, cinnamon, salt and brown sugar.
In another smaller bowl whisk together the coconut oil, mashed sweet potato, greek yogurt, eggs and vanilla.
Pour the wet into the dry and mix until just combined. Stir in the dark chocolate.
Spoon the batter into 12 muffin cups and then top with equal amounts of crumble. Bake for 5 minutes at 425 degrees and after 5 minutes reduce the oven temperature to 350 degrees F. Bake another 20 minutes or until the muffins have popped up are are set in the center.
Allow to cool 5 minutes and remove from the pan to eat or cool completely!