Fluffy Potato Rolls

In a glass measuring cup or small bowl, combine lukewarm water and 1 teaspoon sugar. Sprinkle yeast on top and let sit until foamy, about 5 minutes. Stir yeast into water.  In the bowl of a stand mixer with the dough hook attached, stir together flour, remaining tablespoon sugar, and salt. Add yeast mixture and potatoes. With the mixer running, add butter a tablespoon at a time until fully incorporated. Continue mixing until a smooth dough forms, about 5 minutes.  Grease a large bowl with cooking spray and transfer dough to bowl. Cover with a kitchen towel and let rise until doubled in size, 1 hour.  Punch dough down to deflate, then turn dough out onto a lightly floured surface. Divide dough into 12 equal pieces and roll each into a smooth ball.  Grease a 9”-x-13” baking pan with cooking spray and place balls in pan, leaving an inch between each one. Cover and let rise another 45 minutes.  Preheat oven to 400°. Brush tops of dough with melted butter. Bake until golden, about 25 minutes.  Brush with more melted butter and serve warm.