Step 1

Rinse and peel the sweet potato. Then, cut the potato into 1/2-inch pieces.

Step 2

In a small saucepan over medium-high heat, bring the sweet potato pieces and milk to a boil.

Step 3

Reduce heat to medium-low. Cover the saucepan and cook the potato pieces for 20-25 minutes, or until they are very soft, stirring occasionally so the milk does not scald.

Step 4

Remove from heat and mash the sweet potato with the milk until smooth. Transfer to a medium bowl to cool (about 30 minutes).

Step 5

After the mashed sweet potato has cooled, combine the warm water, yeast, and 1 teaspoon of sugar in a small bowl. Let stand about 5 minutes, or until foamy.

Step 6

In the bowl of a stand mixer with a paddle attachment, add the mashed sweet potato, yeast mixture, eggs, 4 tablespoons of melted butter, and the remaining 3 tablespoons of sugar. Beat on low until combined.

Step 7

Switch to a dough hook attachment and continue mixing on low while gradually adding the bread flour and kosher salt. Beat on low for about 4 minutes, or until the dough is smooth.

Step 8

Turn the dough out onto a lightly floured work surface. Knead the dough by hand for about 5 minutes, adding up to 1/2 cup of flour, as needed, if the dough is sticky.

Step 9

Spray a large bowl with nonstick spray. Place the kneaded dough into the bowl, and cover with plastic wrap.

Step 10

Let the dough rise in a warm, draft-free area until doubled in size, about 1 to 1 1/2 hours.

Step 11

When you are ready, spray a 9x13-inch baking dish with nonstick spray.

Step 12

Punch the dough, turn it out onto a floured surface, and divide the dough into 15 equal-sized pieces.

Step 13

Push down slightly (but firmly and evenly) on the dough pieces and roll the ball under your palm in a circular motion. Use the cupped sides of your hands to keep the dough centered in your palm. You may have to work the dough for a while, but eventually, it will come together and most of the lines and folds should have incorporated into the dough, forming a smooth dough ball.

Step 14

Place the dough balls into the prepared baking dish. Cover with plastic wrap and let rise until doubled in size, about 45 minutes to an hour.

Step 15

Preheat the oven to 375°F.

Step 16

When ready to bake, uncover the rolls and bake for 22 minutes, or until a dark golden brown. (The internal temperature of baked rolls should read 190°F.) When the rolls are almost done, melt the butter for the topping.

Step 17

Brush the baked rolls with the melted butter and evenly sprinkle the kosher salt (or flaky sea salt) over the hot rolls and serve immediately. You could also let the rolls cool on a wire rack before serving. (Note: If you want a sweeter roll, brush the rolls with a mixture of 2 teaspoons maple syrup and 2 teaspoons water to replace the butter.)