Cake:
Preheat oven to 350 degrees F. Melt chocolate, either
on the stove or in the microwave. Set aside.
Beat
butter in large mixer bowl. Add brown sugar and eggs,
and beat until light and fluffy, about 5 minutes. Add
vanilla and melted chocolate, and beat to combine.
Combine
flour, baking soda, and salt. Add to chocolate mixture
gradually, alternating with sour cream. Beat after each
addition.
Stir
boiling water into the batter - the batter will be thin.
Pour into two 9 inch round cake pans which have been
greased and floured.
Bake
for 35 minutes, until cake centre springs back when
touched. Cool for 10 minutes. Remove from pans and cool
completely.
7
Minute Frosting:
In top of double boiler, combine egg whites, sugar,
water, corn syrup and salt. Cook over boiling water,
beating with hand or rotary mixer, until it will stand
in peaks, about 7 minutes.
Remove
from heat, beat in vanilla. Fill and frost cooled cake.