Step #1
Preheat oven to 350 degrees F (175 degrees C).
Step #2 Lightly grease & flour one 9x13 inch pan or two 9 inch round pans.
Step #3 In a small pan melt the butter or margarine with the unsweetened chocolate.
Step #4 Set aside to cool slightly.
Step #5 Cream together the sugar & the eggs until light in color.
Step #6 Add the chocolate mixture to the eggs & temper mixture by beating well (so you don't end up with scrambled eggs!) Add 1 c boiled water (still warm) & mix well.
Step #7 Mixture will be very liquid.
Step #8 Mix together the flour, baking soda, & salt.
Step #9 Add this mixture to the chocolate mixture & mix well.
Step #10 Mix together the vinegar & the milk & stir in theto the chocolate batter.
Step #11 Pour into prepared pan(s).
Step #12 Bake at 350 degrees F (175 degrees C) for 30 mins or until a toothpick inserted in the center comes out clean.
Step #13 Cake divides well for filling with mousse, or ganache, or black forest fillings.
Step #14 The best clue to this cake being nearly done is that you will start to smell the aroma of chocolate filling your house!.