Cook first 4 ingredients in a saucepan over medium-low heat, stirring occasionally, until butter melts. Cool to 105° to 115°.
Combine yeast and 1/2 cup warm water in a 1-cup glass liquid measuring cup; let stand 5 minutes.
Stir together yeast mixture, sour cream mixture, eggs, and flour in a large bowl until well blended.
Chill, covered, 8 hours.
Divide dough into fourths, and shape each portion into a ball. Roll each into 1/4-inch thickness on a floured surface; cut dough with a 2 1/2- to 3-inch round cutter. Brush rounds evenly with 2 tablespoons melted butter. Make a crease across each round with a knife, and fold in half; gently press edges to seal. Place rolls in a 15- x 10-inch jellyroll pan with sides touching.
Cover and let rise in a warm place (85°), free from drafts, 45 minutes or until doubled in bulk.
Bake at 375° for 12 to 15 minutes.