Sift flour & blend with softened butter. Add sour cream & egg yolk.
Divide into 4 equal balls & chill at least 3 hours or overnight in
refrigerator. For filling mix walnuts, sugar & cinnamon. Roll dough
into 4 circles & cut into 12 wedges each. Roll with 1/2 ts of filling
at outer edge of wedge (wide end). Brush with egg white & dip in
sugar mixture to coat top. Bake at 400°F about 20 minutes on lightly
greased sheet.
