Whichever method you choose, make sure the sweet potatoes are smooth and cooled slightly before mixing them into the batter. Warm potatoes can melt the butter too soon and change the texture of your muffins.
Use mashed sweet potatoes, not sweet potato pie filling. The pie filling is already sweetened and seasoned.
Measure the sweet potato puree after mashing for the most accurate results.
Don't overmix the batter. Stir just until the ingredients are combined to keep the muffins tender.
A toothpick inserted into the center should come out with a few moist crumbs, not wet batter.
Brush the tops with honey butter while they're still warm for extra flavor and moisture.
