In a large bowl, beat butter with an electric mixer on medium to high speed for 30 seconds. Add brown sugar and salt. Beat until combined, scraping side of bowl occasionally. Beat in flour until mixture resembles coarse cornmeal. Beat in sour cream until mixture is moistened and starts to cling. Gather mixture into a ball. Divide into three portions.

On a lightly powdered-sugared surface, roll out one of the dough portions into a 9-inch square. Spread with about 2 tablespoons of the jam; sprinkle with one-third of each of the coconut, walnuts, and currants. Roll up into a spiral; pinch edge to seal. Wrap in plastic wrap or waxed paper. Repeat with the remaining dough, jam, coconut, walnuts, and currants. Chill for 2 to 3 hours or until firm enough to slice.

Preheat oven to 400 degrees F. Line a large cookie sheet with parchment paper, nonstick foil, or foil lightly coated with nonstick cooking spray; set aside. Using a serrated knife, cut rolls into 1/2-inch-thick slices. Place slices 1 inch apart on prepared cookie sheet.

Bake in the preheated oven about 12 minutes or until tops are lightly browned. Transfer cookies to a wire rack. While warm, sprinkle lightly with powdered sugar. Cool completely on wire rack. Makes about 48 cookies.

To Store: Layer cookies between waxed paper in an airtight container; cover. Store in the refrigerator for up to 3 days or freeze for up to 1 month.