Heat oven to 400.
Cut softened butter into flour...Add egg yolks and sour cream.Add 1 tsp vanilla. Mix well...Divide dough into 8 parts. Roll each part into a circle on a board dusted with conf sugar. Cut into 8 wedges. Beat 3 egg whites till stiff. Add 3 tbl conf sugar and fold in 1 tsp vanilla. Brush rolled dough with egg. Sprinkle with cinnamon and sugar... Roll each wedge loosely...Brush slices with egg white and sprinkle wth cinnamon and sugar. Bake on greased cookie sheet 10-12 min