Melt at low heat or over double boiler (or in microwave): 1/2 cup butter 2 one oz. squares of unsweetened chocolate Remove from heat. Add: 1 cup sugar Blend in 2 eggs, one at a time Add 1 tsp. vanilla Stir in 3/4 cup sifted flour Add 1/2 cup chopped nuts Mix it all well. Spread in 8X8X2 inch pan, well greased. Bake at 350 degrees for 30 minutes. Be careful not to overbake. Cool and sprinkle with powdered sugar.