Make the pastry:
1. With an electric mixer on medium speed, blend the sour crem and butter until smooth, about 2 minutes. Add the flour and salt and blend until the dough comes together, about 30 seconds.
2. Form the dough into 2 disks, wrap in plastic and chill overnight.
3. Remove the dough from the refrigerator and let soften slightly, for about 10 minutes. Preheat oven to 350 degrees F, with a rack in the middle. Lightly grease a baking sheet.
4. On a lightly floured surface, roll out each disk to a circle about 9 to 10 inches in diameter and less than 1/8 inch thick.
Prepare the Filling:
5. Spread 1/3 cup apricot jam over the surface of 1 disk, leaving a 1/4 inch border around the edges. Sprinkle 1/3 cup of the walnuts, 1 tablespoon of the raisins and 1 tablespoon of the golden raisins over the jam.
6. Roll up the dough jelly-roll fashion, pinching the ends together. Carefully lift the roll with your hands and transfer to the baking sheet. With a sharp knife, slice the roll halfway through into about 12 sections.
7. Repeat the procedure with the remaining dough and filling.
8. Bake for 40 to 45 minutes, or until golden brown. Cool on the baking sheet for 5 minutes. Cut the slices through; cool completely on the sheet. Store in an airtight container for up to 1 week or freeze for several months.