Preheat your oven to 350°F. Line a muffin tin with paper liners or grease it lightly.
In a large bowl, combine the mashed sweet potato, mashed avocado, honey (or maple syrup), eggs, and vanilla extract. Mix until smooth and well combined.
In another bowl, whisk together the almond flour, cocoa powder, baking soda, and salt.
Gradually add the dry ingredients to the wet ingredients, stirring until just combined. If using, fold in the dark chocolate chips.
Spoon the batter evenly into the prepared muffin tin, filling each cup about 3/4 full.
Bake for 20-25 minutes, or until a toothpick inserted into the center comes out clean. Allow the muffins to cool in the pan for 5 minutes before transferring them to a wire rack to cool completely.