Chocolate Cake

3 oz (85g)	fine-quality semisweet chocolate such as Callebaut
1 1/2 cups (355mL)	hot brewed coffee
3 cups (600g)	sugar
2 1/2 cups (315g)	all-purpose flour
1 1/2 cups (~130g)	unsweetened cocoa powder (not Dutch process)
2 tsp (10g)	baking soda
3/4 tsp (4g)	baking powder
1 1/4 tsp (7g)	salt
3	large eggs
3/4 cup (175mL)	vegetable oil
1 1/2 cups (355mL	well-shaken buttermilk
3/4 tsp	vanilla
two	10 inch round cake pans (157 square inches)

Preheat oven to 300°F and grease pans. Line bottoms with rounds of wax paper and grease paper.
Finely chop chocolate and in a bowl combine with hot coffee. Let mixture stand, stirring occasionally, until chocolate is melted and mixture is smooth.
Into a large bowl sift together sugar, flour, cocoa powder, baking soda, baking powder, and salt.
In another large bowl with an electric mixer beat eggs until thickened slightly and lemon colored (about 3 minutes with a standing mixer or 5 minutes with a hand-held mixer).
Slowly add oil, buttermilk, vanilla, and melted chocolate mixture to eggs, beating until combined well.
Add sugar mixture and beat on medium speed until just combined well.
Divide batter between pans and bake in middle of oven until a tester inserted in center comes out clean, 1 hour to 1 hour and 10 minutes.
Cool layers completely in pans on racks. Run a thin knife around edges of pans and invert layers onto racks.
Carefully remove wax paper and cool layers completely. Cake layers may be made 1 day ahead and kept, wrapped well in plastic wrap, at room temperature.

“Double Chocolate Layer Cake”, Gourmet magazine, March 1999. Similar recipe with buttercream frosting on The Merry Gourmet blog.

2014-10-12: Amount for 2 8inch rounds (multiplied ingredients by 2/3 and rounded baking soda)

2 oz (85 g)	72% dark chocolate
1 cup	hot brewed coffee
2 cups (400g)	sugar
1 2/3 cups (210g)	all-purpose flour
1 cup (87g)	unsweetened cocoa powder (not Dutch process)
1.5 tsp	baking soda
1/2 tsp	baking powder
3/4 tsp	salt
2	large eggs
1/2 cup	vegetable oil
1 cup	well-shaken buttermilk
1/2 tsp	vanilla

2021-07-08: Used the 2/3 amounts specified above (105 in²) for each layer of 9*13 cake (117 in²).
Proportions for two 8” round pans, from The Merry Gourmet blog.

2 ounces	bittersweet or semisweet chocolate (no more than 60% cacao), chopped
3/4 cup	cocoa powder (Dutch process is preferred)
1 cup	boiling water
1-3/4 cup	all-purpose flour
2 cups	granulated sugar
2 tsp	baking soda
1 tsp	baking powder
1 tsp	coarse salt
1 cup	buttermilk
1/2 cup	vegetable oil
2	eggs, room temperature
1-1/2 tsp	vanilla extract