5 Sweet Potato Prep: Wash, dry, and poke the Japanese sweet potato all over with a fork. Add it to a baking sheet and roast it at 400F (204C) until soft, about an hour. Cook time will depend on the size - I used 3 small ones. You can do this step up to 3 days in advance and store them in the fridge. Preheat your oven to 350F (175C). Line a muffin tin with 6 liners or grease well.
1 In a large bowl, mash the cooked Japanese sweet potato until smooth. Add the eggs, milk, maple syrup or honey, and vanilla. Mix well.
2 Add the flour, baking powder, baking soda, salt, and cinnamon (if using) to the bowl. Stir gently until just combined. Do not overmix.
3 With a large cookie scoop, divide the batter evenly into 6 muffin cups, filling each about 3/4 full.
4 Bake for 18-22 minutes at 350F (17%C), or until a toothpick inserted in the center comes out clean. Mine took 22 min. Let cool in the pan for 5 minutes before transferring to a wire rack.
