In the top of a double boiler, stir chocolate, oil, salt and coffee over barely simmering water until blended.
Pour mixture into a large bowl and add sugar, egg, buttermilk, baking soda, and vanilla; beat on medium speed until well blended. Add flour and continue beating for 5 minutes, occasionally scraping sides down with rubber spatula.
Pour into a greased and floured 8-inch cake pan. Bake at 350 degrees until cake begins to pull from sides of pan, about 30 minutes. Set on rack to cool, then remove from pan.
If you like, wrap cool cake and freeze as long as one week. Thaw, uncovered at room temperature before proceeding.
Cut cake in half horizontally to make 2 layers. Combine apricot preserves and brandy; spread evenly over bottom layer of cake. Set top layer in place and put cake on a rack.
In the top of a double boiler over barely simmering water, stir semi-sweet chocolate with shortening until melted.
Slowly pour chocolate frosting onto center of cake so it flows over the entire surface. With a spatula, guide icing down over sides of the cake to coat smoothly. Chill until the icing is set, at least 30 minutes.
Using a wide spatula, loosen cake from rack and gently slide onto serving plate.
If cake is made ahead, cover without touching and chill up to 6 hours; return to room temperature to serve. Makes about 10 servings
Notes
If you want a little more wiggle room in terms of frosting, the proportions can be increased to 8 ounce semi-sweet chocolate and 2 tablespoons shortening.