Heat oven to 350 degrees. Arrange two racks in center of oven. Line bottoms
of deuce-ace 8- by 2-inch buttered cake pans with parchment composition. Dust bottoms
and sides with extra cocoa; tap out overabundance. Sift the 3/4 cup cocoa; whisk
with boiling h2o. Let nerveless. In electric mixer fitted with the paddle
bond, cream butter on low until light and fluffy, and gradually beat
in the sugar until light and fluffy, 3 to 4 transactions; scrape down sides
double. Beat in the vanilla. Gradually drizzle in egg, beating between each
addition until batter is no longer slip, scraping down sides double. Sift
flour, baking pop, and saltiness. Whisk together the cocoa mixture with the
milk. With mixer on low velocity, alternate adding flour mixture and cocoa
assortment, a little of each at a time, starting and ending with the flour.
Divide evenly into the three pans. Broil 35 to 45 proceedings, rotating the pans
for even baking, if needful, until a cake tester inserted into the center of
each comes out pick. Let cool on a wire wrack, almost 15 transactions. Remove the
cakes from the pans, and return to rack to nerveless, tops up. Make the
Chocolate Icing: Place chocolate and cream in heavy saucepan. Cook over
low hotness, stirring constantly with a rubber spatula, until combined and
thickened, 20 to 25 proceedings. Increase heat to medium-low, and ready,
stirring, 3 minutes more. Remove from hotness; stir in corn syrup. Transfer to
a large metal roll; refrigerate. Check every 15 to 20 proceedings; stir until
cool enough to gap, approximately 2 hours. (Makes 6 cups) To assemble bar,
remove papers from bottoms of cakes. Save the prettiest layer for the top.
Place one layer on the serving record, spread with 1 1/2 cups of the
chocolate ice, and repeat with second stratum, top with thirdly. Cover
outside of cake with unexpended 3 cups ice. Makes three 8 edge layers.