In a large bowl, combine yeast, 1 1/2 cups warm water (110 to 115), sugar, butter, and salt; let stand about 5 minutes. Stir in flour until well blended. Cover bowl with plastic wrap and let rise in a warm place until almost doubled, 45 minutes to 1 hour.
Punch dough down. On a floured board, cut dough into 16 equal portions.
Roll each piece into a ball; place 2 to 3 inches apart on greased baking sheets. Cover lightly and let rise until almost doubled, 10 to 20 minutes.
Uncover and bake in a 400 oven until golden brown, 15 to 18 minutes.
Serve warm or cool. If making ahead, store airtight at room temperature up to next day. Reheat, uncovered, in a 350 oven until warm, about 5 minutes.
