Preheat oven to 300 F. Cream butter and sugar. Add eggs, one at a time, beating well. Add vanilla. Sift flour with salt and add to butter mixture. Add half of the nuts. Spread in a greased but not floured 9-by-13-inch pan. Spread batter fairly thin. Sprinkle with remaining nuts. Bake for 30 minutes. Cut while hot but leave in pan to cool. Yields 48 cookies.