Combine the butter, sugar, egg yolks, rolled oats, baking powder, and vanilla and beat well. Whip the egg whites until they are stiff and fold them and the salt into the other ingredients. Drop by teaspoonfuls, 8 cm apart, onto a nonstick cookie sheet. Bake 190ºC for 10 min. Cal: 53, Fat: 0.2g. ----