In a mixing bowl, cream butter and cottage cheese until smooth; gradually add flour. Cover and refrigerate for 2 hours or until easy to handle. On a lightly floured surface, roll out to 1/8-in. thickness. Cut with a 2-in. round cookie cutter dipped in flour. Place 1 in. apart on ungreased baking sheets. Brush tops with egg. Combine walnuts, sugar and cinnamon; sprinkle over cookies. Bake at 350 degrees F for 15-20 minutes or until golden brown. Remove to wire racks to cool.