In a microwave safe bowl, melt chocolate in 30 second intervals until almost fully melted. Add coconut oil and melt for final 20 seconds and stir together until fully combined.
In another microwave safe bowl, microwave nut butter for 20 seconds until slightly runny. Mix into chocolate mixture and stir until mixture is uniform.
Pour mixture into silicone molds (or parchment lined 9x5 loaf pan), add desired toppings/sprinkles, and allow to set in the freezer for 2 hours, until mixture is completely solid. Cut into desired number of pieces (or pop out of molds) and enjoy! Store in the freezer or fridge.