3 sq. unsweetened chocolate
1/4 c. (1/2 stick) butter
3 1/2 c. sifted powdered sugar
1 egg
2 tsp. vanilla
1 c. chopped nuts (optional)

Melt chocolate and butter. Add about 1/2 of the sugar to the chocolate mixture and mix well. Beat in egg and vanilla. Gradually work in rest of sugar; add nuts.

Press into 8-inch square pan lined with waxed paper. Let set until firm. Turn out and cut into squares.