Butter Horns

2 cups flour
1/2 lb butter
1 cup sour cream
1 egg yolk
Mix together and than separate into 10 pieces. Wrap individually in wax paper and refrigerate over-night. Make a mixture if cinnamon, sugar and chopped nuts. Flour board and roll out one piece of dough into a circle. Divide with a knife into 8 pie shaped pieces and sprinkle with the sugar mixture mixture. Roll from outside toward middle. Repeat with all dough. Place on cookie sheets bending slightly to form the horn. Bake in 375 oven for 15-20 minutes. Use an ungreased cookie sheet.