1. – Preheat your oven to 375°F (190°C) and line a baking sheet with parchment paper.

2. – In a medium saucepan, cover the cubed sweet potatoes with water and bring to a boil. Reduce heat and simmer until the potatoes are tender, about 15 minutes. Drain the potatoes and mash them until smooth.

3. – In a large bowl, combine the warm water, yeast, and sugar. Let the mixture sit for 5-10 minutes until foamy.

4. – Add the mashed sweet potatoes, salt, and 2 cups of the flour to the yeast mixture. Using a wooden spoon or your hands, mix until a shaggy dough forms.

5. – Turn the dough out onto a lightly floured surface and knead for about 5 minutes, adding more flour as needed, until the dough is smooth and elastic.

6. – Place the dough in a lightly greased bowl, cover with a damp towel, and let rise for 1 hour or until doubled in size.

7. – Punch down the dough and divide it into 12 equal pieces. Shape each piece into a smooth bun and place them on the prepared baking sheet, spacing them about 2 inches apart.

8. – Cover the buns and let them rise for an additional 30 minutes.

9. – Brush the tops of the buns with the melted butter.

10. – Bake for 18-20 minutes, or until the tops are golden brown.

11. – Remove the buns from the oven and let them cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.