- Dissolve yeast in warm water in a large mixing bowl; let yeast mixture stand 5 minutes.
- Add ¾ cup sugar, melted butter, 2 beaten eggs, and ½ teaspoon salt to yeast mixture, and beat at medium speed of an electric mixer until ingredients are well blended.
- Gradually add 3½ cups flour, beating until mixture is smooth (dough will be sticky)
- Place dough in a well-greased bowl, turning to grease top.
- Cover and let rise in a warm place (85'), free from drafts, 1½ hours or until doubled in bulk.
- Punch dough down; turn out onto a lightly floured surface, and knead until dough.
- Is smooth and elastic (2 to 3 minutes).
- Shape dough into 18 balls, and place 2 inches apart on greased baking sheets.
- Flatten each ball slightly.
- Combine 1 cup sugar, 1 cup flour, ground cinnamon, and ⅛ teaspoon salt in a medium mixing bowl; cut in ½ cup butter with a pastry blender until mixture resembles coarse meal.
- Stir in egg yolk.
- Shape mixture into 18 balls; roll each ball to a 3-inch circle on a lightly floured surface.
- Using a metal spatula, place one circle on top of each roll (circles should completely cover the top of each roll).
- Score through topping and halfway through roll with a sharp knife, forming a swirl or a crisscross design.
- Cover and let rise in a warm place, free from drafts, 30 minutes or until doubled in bulk.
- Bake at 400°F for 10 minutes or until lightly browned.