Sweet Potato Rolls

Place sweet potato and water in a medium saucepan; bring to a boil over high heat. Reduce heat to maintain a simmer and cook until the sweet potato is tender, 10 to 12 minutes. Reserve 1/4 cup cooking liquid in a small bowl. Drain and transfer the sweet potato to a food processor. Add oil, vinegar and salt and puree, scraping down the sides of the bowl as needed, until smooth, about 1 minute.

Combine warmed milk, yeast and sugar in a small bowl; let stand 5 minutes. Add the yeast mixture, flour and 1 teaspoon caraway seeds to the food processor. Pulse until a slightly sticky dough forms. If it is too dry, add the reserved cooking liquid, 1 tablespoon at a time, with the motor running, just until the dough forms a ball.

Transfer the dough to a lightly floured surface and knead for 2 minutes, sprinkling with more flour if it sticks. Shape into a ball and transfer to a bowl coated with cooking spray. Cover with plastic wrap and let rise in a warm, draft-free place until the dough doubles in size, about 1 hour.

Coat a 9-by-13-inch baking pan with cooking spray.

Punch down the dough and divide into 15 equal pieces. Roll each piece into a ball and place in the prepared pan. Cover with plastic wrap and let rise until almost doubled, about 45 minutes.

Preheat oven to 375 degrees F.

Brush the rolls with butter and sprinkle with the remaining 1/2 teaspoon caraway seeds and flaky salt. Bake until light golden brown, 25 to 30 minutes. Let cool in the pan for 10 minutes. Turn out onto a wire rack. Serve warm or at room temperature.