6Tbspunsweetened cocoa powder (NOT Dutch processed)33 g
½cupboiling water120 g
¼cupwhole milk60 ml
½tspvanilla extract2½ ml
1cupall-purpose flour125 g
⅔tspbaking soda3 g
½cupunsalted butter (1 stick), softened113 g
½cupdark brown sugar120 g
½cupgranulated sugar100 g
FOR THE FROSTING
1⅔ouncesunsweetened chocolate48 g
¼cupunsalted butter (½ stick)57 g
⅓cwhipped cream cheese75 g
½tsppure vanilla extract2½ ml
13Tbsppowdered sugar (¾ cup + 1 Tbsp)104 g
Heat the oven to 350˚F/190˚C. Butter 2 standard loaf pans (8 1/2 x 4 1/2 x 2 1/2 inches, or 21 x 11 x 6 cm) and line them with waxed or parchment paper. Butter the paper and then dust the pans lightly with cocoa powder.
MAKE THE CAKE LAYERS
Measure the cocoa powder into a bowl, and whisk in ½ cup boiling water until it is smooth, dark, and very glossy. Whisk in the milk and vanilla.In another bowl, whisk the flour with the baking soda and ¼ teaspoon salt.
Put the butter into the bowl of a stand mixer, and beat in both sugars until the mixture is light, fluffy, and the color of coffee with cream – about 5 minutes. One at a time, beat in the eggs, beating about 30 seconds after each one, before adding the next.On a low speed, beat in the flour mixture, alternating with the cocoa mixture, starting and ending with the flour (flour-cocoa-flour-cocoa-flour). The batter may look curdled, but that’s okay.
Pour half the batter into each pan and smooth the tops. Bake in the middle of the oven about 25 minutes, until a tester comes out clean of crumbs. (The color and material of your loaf pans will affect the time needed.) When the cake is done, remove the pans from the oven, and place on racks to cool. Let them cool 10-15 minutes, and then turn out the cakes from the pans, and let them continue cooling on the rack until they are completely cool.
Chop the chocolate and melt it in a double boiler. Let it cool enough that you could put the pan on your open palm with no discomfort at all.
Mix the butter with the whipped cream cheese. Add the cooled chocolate, the vanilla, and a pinch of salt, and stir thoroughly. Mix in the powdered sugar and, using the mixer again, beat well until the frosting is light and fluffy – at least 5 minutes
ASSEMBLE THE CAKE
When the cake layers are completely cool, it’s time to assemble the cake. Put one layer on a rectangular plate. Spread about one third of the frosting on that layer, then put the second layer on top and frost the whole thing.
This cake will serve 8 to 10 people, depending on how you slice it.
This cake takes well to the freezer, even in the frosted state. Freeze slices, then once frozen, wrap well. To serve from frozen: unwrap each slice, then warm in the microwave (carefully) or leave out to come to room temperature.