Don't skip cooling the sweet potatoes completely — it is the difference between pillowy gnocchi and dense bricks. Freeze uncooked gnocchi in a single layer on a baking sheet, then transfer to a zip-top bag for up to 3 months; cook straight from frozen, adding an extra minute or two once they float. Leftovers reheat best in a hot skillet with a little butter or oil to re-crisp the edges. For gluten-free, use a 1-to-1 gluten-free flour blend. For dairy-free, use high-fat vegan butter or olive oil, and substitute nutritional yeast for the Parmesan.