Cream together butter and sugar. Add eggs one at a time, beating after each addition.
In another bowl sift flour, salt and baking powder together. Blend in to the creamed mixture and then add 1/2 teaspoon vanilla to the dough.
Spread dough in a greased 20x30cm baking pan and sprinkle chopped nuts over top.
In a small mixing bowl beat egg white until stiff but not dry. Add brown sugar and 1/2 teaspoon vanilla to the whipped egg white and beat thoroughly. Spread meringue over the dough and nuts already in the pan.
Bake at 190 degrees C for 20 to 30 minutes. Cool and cut into bars.