Place in saucepan and stir until mixed. Set aside to cool.

1/2 c. boiling water
1/4 c. butter
1 square chocolate

Sift 3 times and add to saucepan and mix.

1 c. cake flour
3/4 tsp. baking soda
1/4 tsp. salt
1 c. sugar

Add to mixture and mix.

1/4 c. sour cream
1 beaten egg
1 tsp. vanilla

Place in buttered 9 x 9 inch pan lined with waxed paper. Bake at 375 degrees for 45 minutes.