Mix sour cream and yeast in small bowl. Melt butter and shortening in saucepan, cool to lukewarm.
Put flour in large mixing bowl, add sour cream mixture, butter mixture, egg yolks and egg. Mix thoroughly. Cover bowl and chill overnight.
Prepare filling by placing apricots and sugar in small saucepan with enough water to cover. Bring almost to boil, reduce heat to low, cover and simmer about 45 minutes, or until tender. Puree stewed apricots with liquid in food processor or blender.
To form Roskis (pronounced ROOS-skees) scoop out a baseball-size piece of the stiff dough. Form into a ball. Sprinkle about 1/3 C sugar onto rolling surface, then roll into a circle.
Sugar will become embedded in the dough. Cut circle into about eight wedge-shaped pieces. At the wide end of each wedge, place 1/4 tsp. filling. Starting at wide edge, roll dough to point of wedge, in the fashion of a crescent roll.
Place roskis about 1-inch apart on baking sheet lined with foil. Repeat with more sugar and dough until all dough is used.
Bake at 350º degrees. 20-25 minutes, or until lightly brown.
Variation: Substitute strawberry jam or pineapple pie filling for apricots.