With pastry blender, cut butter into flour till mixture resembles fine crumbs.
Combine egg yolk and sour cream; blend into flour mixture.
Chill dough several hours or overnight.
Divide dough into four equal portions, keeping each part refrigerated till ready to use.
Roll each part to 10-inch circle on lightly floured surface.
Spread with 2 tablespoons of the apricot preserves; sprinkle with 2 tablespoons of the coconut and 1 tablespoon of the nuts.
Cut each circle into 12 wedges with fluted pastry wheel.
Starting from wide end, roll each wedge into a crescent.
Sprinkle with a little granulated sugar.
Place on ungreased cookie sheet.
Bake in 350° oven for 20 minutes or till lightly browned.
Remove from sheet; cool on rack.