Nut-Filled Butterhorns

In a large mixing bowl, dissolve yeast in warm milk. Add sugar; let stand for 5 minutes. Add butter, cream cheese, cream, sour cream, egg yolks, salt and 2-1/2 cups flour. Beat until smooth. Stir in enough remaining flour to form a soft dough. Turn onto a floured surface; knead until smooth and elastic, about 6-8 minutes. Place in a greased bowl, turning once to grease top. Cover and refrigerate overnight.

In a mixing bowl, beat egg whites until foamy. Add cream of tartar; beat until soft peaks form. Gradually add 2 tablespoons sugar, beating until glossy stiff peaks form. Fold in nuts.

Divide chilled dough into fourths. On a lightly floured surface, roll each portion into a 12-in. circle; spread a fourth of the filling over each circle. Add cinnamon to remaining sugar; sprinkle over filling. Cut each into 12 wedges. Roll up wedges from the wide end; place pointed side down 3 in. apart on greased baking sheets. Curve ends to form a crescent shape.

Bake at 350 for 17-20 minutes or until golden brown. Remove from pans to wire racks to cool. Combine icing ingredients; drizzle over rolls.