Mix butter, 1 cup sugar, egg & flavoring. Stir together flour & powder; stir into mixture. Chill dough. Heat oven to 375. Roll dough 1/16" thick on lightly floured cloth covered board. Cut with small cookie cutter. Place on ungreased sheet. Beat white slightly with fork. Brush over cookie. Brush with mixture of 1/4 cup sugar & cinnamon. Bake 8-10 minutes.