Set aside 1/2 cup flour for kneading. With a sturdy wooden spoon, stir eggs, yeast mixture and half the remaining flour into the lukewarm milk mixture until smooth. Add remaining flour, beating well with a wooden spoon until dough pulls away from the sides of the bowl. You should have a somewhat stiff dough. Turn dough onto a lightly floured surface. Dust hands lightly with flour; shape dough into a ball. Flatten slightly, then knead several minutes until smooth and elastic; it should bounce back when gently pressed with a finger. Dust top lightly with flour; cover with a clean cloth and let rest, 15 minutes.
While dough rests, line a 9- by 13-inch baking pan with 2 pieces of aluminum foil, 1 crosswise, 1 lengthwise; leave ends loose to make removing the baked rolls from pan easier. Brush foil well with some of the melted butter. Prepare a filling.
Pat down dough; roll into a 12- by 18-inch rectangle. Brush lightly with melted butter. Sprinkle or spread with filling of your choice, leaving a 1/2-inch space along the edges. Starting from long side nearest you, roll dough up tightly; pinch long seam closed. Cut roll into 1 1/2-inch slices using a sharp knife. Or use a 12-inch piece of sturdy thread to cut slices: Place thread under roll at a 1 1/2-inch mark. Pick up thread ends — thread on the right with your left hand, thread on the left with your right hand — and pull thread ends across roll to cut. You should have 12 rolls. Arrange cut rolls in prepared baking pan, leaving space between them. Brush tops with remaining melted butter. Cover pan with plastic wrap; refrigerate overnight.
Remove rolls from refrigerator; carefully remove plastic wrap. Heat oven to 375 degrees. Let rolls stand at room temperature, 15 to 20 minutes. (Do not let them get too puffy before baking.) Bake until tops are nicely browned, 25 to 30 minutes. Cool in pan on a rack, 5 minutes. Use ends of foil as handles to remove rolls from pan. Remove rolls from the foil, with help from a spatula. Place on a serving tray; cool, 10 minutes. Drizzle with icing before serving.
Cinnamon-pecan-raisin: Mix 3/4 cup granulated sugar with 1 1/2 tablespoons ground cinnamon. Mix in 1/2 cup chopped pecans and 1/2 cup raisins or dried cranberries.