Cream butter and sugar gradually, then bake with an optional meringue topping.

Steps

1. Cream butter and sugar gradually.
2. Beat egg yolks with 1 tsp water for each yolk; add vanilla.
3. Sift flour and baking powder; add after eggs to butter mixture.
4. Spread in a baking tin.
5. Optional: sprinkle with nuts (walnuts).
6. Beat egg whites very stiffly with 1/4 cup sugar.
7. Spread over mixture; bake about 25 minutes at 350°F. Cool and cut in squares.