Line mini muffin pan with 12 paper liners, set aside.In a medium microwave safe bowl, melt chocolate chips and coconut oil in about 20 second increments, stirring in between until chips have completely melted. (You can also melt in a small saucepan on stove over low heat, or a double boiler. Just be careful not to burn your chips whichever method you prefer!)Scoop just a little less than ½ tablespoon of melted chocolate into 12 muffin liners. Transfer pan to freezer and allow chocolate to set for 5 minutes.While bottom chocolate layer sets, make your filling: In a small bowl, microwave coconut butter with mashed purple sweet potato Set aside.Take muffin pan out of freezer. Using ½ teaspoon, scoop a rounded ball of sweet potato coconut butter (equal to about 1 tsp) and place on solid chocolate. Gently press butter down a little bit with back of teaspoon to flatten. Cover in more melted chocolate, about another ½ tablespoon. Transfer pan back to freezer for another 5 minutes until set.I like to store my chocolate cups in the fridge, then allow to come to room temperature before eating. Enjoy!