1. Make the buns: Dissolve the yeast in the lukewarm water and set aside.

2. In a large bowl, cream together the butter and granulated sugar. Add the egg yolks. Blend in the vinegar and sour cream. Add the dissolved yeast and then the flour and mix very well. The dough should be heavy, but not pasty. Turn out the dough onto a floured board and knead for 10 minutes. Divide the dough in half, shape each half into a ball, wrap each ball in plastic, and refrigerate for at least 6 hours or up to 3 days.

3. Preheat the oven to 425°F. Lightly butter 24 muffin cups.

4. Make the filling: In a mixing bowl, cream the butter with half of the brown sugar. Place 1 teaspoon of this mixture in the bottom of each buttered muffin cup. Set 2 pecan pieces in each.

5. Remove the dough from the refrigerator. Roll out each half on a floured board into a rectangle 18 inches wide, 10 inches long, and about ¼ inch thick.

6. Sprinkle each sheet of dough with the remaining ½ cup brown sugar, the 1 tablespoon cinnamon, and the raisins. Roll up the dough as would a jelly roll and cut into 1½-inch slices. (Each sheet should yield 12 slices.)

7. Place each slice of dough in a muffin cup with one of the spiral sides up. Bake until browned and fragrant, 20 minutes. Let cool briefly, carefully turn out, making sure the topping comes with the schnecken. Sprinkle with a little additional cinnamon. Serve at room temperature.