Peel and cube 1 medium sweet potato. Boil until fork-tender (about 15 minutes), drain well, and mash until smooth. Let cool to room temperature.

In a large bowl, combine all-purpose flour, instant yeast, sugar, and salt.

Warm milk and butter in the microwave until butter is melted. Add the mashed sweet potato and egg, milk and butter to the dry mixture.

Mix until a shaggy dough forms, then knead on a lightly floured surface for 6-8 minutes until smooth and elastic. The dough will be slightly sticky but should still be workable.

Place in a lightly oiled dish, cover and allow to rise in a warm place for 1 ½ - 2 hours.

Once risen, punch down the dough and divide into 9 equal pieces. Shape each piece into a ball by pulling the edges toward the center and pinching to seal, then rolling gently between your palms.

Place all balls into a greased square baking dish, cover and allow to rise for another 45-60 minutes.

Preheat oven to 375°F. Brush tops with egg wash (1 egg + 1 tablespoon water), then bake for 18-22 minutes, until golden.

Allow to cool fully and enjoy!