How to Make It
Heat milk and 1/2 cup butter in a small saucepan over medium-low heat just until butter melts. Remove from heat, and cool mixture until a thermometer registers 100° to 110° (about 10 minutes).
Stir together yeast, 1/2 cup warm water (100° to 110°), and 1 tsp. sugar in a glass measuring cup, and let stand 5 minutes.
Beat eggs at medium speed with a heavy-duty electric stand mixer; add 1/2 cup sugar and 1 tsp. salt, beating to combine. Add milk mixture and yeast mixture, beating until combined. Reduce speed to low, and gradually add flour, beating until blended. Place dough in a large lightly greased (with cooking spray) bowl, turning to grease top. Cover with plastic wrap, and chill 8 hours to 5 days.
Turn dough out onto a lightly floured surface, and knead 2 to 3 times. Gently shape dough into 72 (1-inch) balls.
Place 3 dough balls in each cup of 2 lightly greased (with cooking spray) 12-cup muffin pans. Microwave remaining 1/2 cup butter in a microwave-safe bowl at HIGH 1 minute or until melted. Brush rolls with half of melted butter.
Cover muffin pans with plastic wrap, and let rise in a warm place (80° to 85°), free from drafts, 45 minutes to 1 hour or until doubled in bulk.
Preheat oven to 375°. Bake rolls for 11 to 13 minutes or until golden brown. Brush with remaining melted butter.