Dough

1. In a large mixing bowl, dissolve yeast in warm water; let stand for 5 minutes.
2. Add all dough ingredients except flour, beat until thoroughly mixed (medium speed of electric mixer).
3. Slowly add 3 1/2 cups flour, beat until smooth. Put dough into a greased bowl, turning over to grease all sides.
4. Cover, let rise in a warm place, about 1 1/2 hours or until doubled.
5. Punch dough down, put on lightly floured surface, knead until smooth and elastic (about 3 minutes).

Topping and Baking

1. Make dough into 18 balls; set 2 inches apart on greased baking sheets. Flatten each ball slightly.
2. Combine all topping ingredients except butter and yolk in medium bowl; cut in butter until mixture resembles coarse meal. Add yolk and mix well. At this point if you desire various color tops, divide the dough and add paste food color.
3. Make 18 balls; roll each to about a 3-inch circle on lightly floured surface. Place a circle on each roll, covering surface.
4. With a knife, slash through topping and halfway through roll in swirl pattern like a seashell.
5. Cover, let rise in a warm place, 30 minutes or until doubled.
6. Bake at 400 degrees F for 10 minutes or until lightly browned.