Hot Fudge Sauce:

1 (4 oz.) bar German chocolate
1/2 oz. unsweetened chocolate
8 tbsp. butter (1 stick)
3 c. powdered sugar
1 2/3 c. evaporated milk
1 1/3 tsp. vanilla

Melt the German chocolate with the butter in a saucepan over very low heat. Stir in the powdered sugar, alternating with evaporated milk and blending well. Stirring constantly, bring the mixture to a simmer over medium heat. Simmer until the mixture becomes thick and creamy, about 8 minutes. Stir in the vanilla. Serve slices of cake topped with warm fudge sauce and ice cream, if desired.

Cake:

1 tsp. baking soda
1/2 tsp. salt

Preheat oven to 350°F. Cream the brown sugar with the shortening with an electric mixer. Add the buttermilk and vanilla then the melted chocolate. With the mixer running, add eggs, 1 at a time. Sift the flour with the baking soda and salt. Add the dry ingredients to the sugar mixture and beat for 2 minutes. Grease and flour a 13 by 9 by 2 inch cake pan. Pour the batter into the prepared pan and bake until the cake is springy and a toothpick can be inserted and removed cleanly, about 40 minutes. Allow cake to cool for 10 minutes then turn it out onto a rack to finish cooling.