In a mixing bowl, dissolve yeast in warm water and sugar. Let stand for about 10 minutes, until yeast is starting to foam.
Add 2 cups flour and salt. Mix for 2 minutes. Add egg and butter, mix well. Stir in enough remaining flour to form a soft dough . Place dough in a greased bowl, turning once to grease top. Cover and refrigerate overnight.
Punch dough down. Turn onto a lightly floured surface; divide into 24 pieces. Shape each into a ball. Place 2 in. apart on greased baking sheets. Cover and let rise in a warm place until doubled, about 2 hours.
Pre-heat oven to 400°
Bake at 400° F for 12-15 minutes or until golden brown. Remove from pans to wire racks to cool.