| | CAKE |
| 1/2 | c | Unsweetened Dutch-process cocoa powder |
| 2 | tb | Boiling water |
| 2 | oz | Unsweetened chocolate; chopped |
| 3/4 | c | Milk |
| 1 | c | (2 sticks) unsalted butter; softened slightly |
| 2 | c | Sugar |
| 4 | lg | Eggs; separated |
| 2 | ts | Vanilla extract |
| 2 | c | All-purpose flour |
| 1 | ts | Baking powder |
| 1 | ts | Baking soda |
| 1 | ts | Salt |
| | FILLING |
| 1 | tb | Plus 1 3/4 teaspoons unsweetened Dutch-process cocoa powder |
| 2 | c | Boiling water |
| 3/4 | c | Plus 1 tablespoon plus 1/2 teaspoon sugar |
| 1 | oz | Bittersweet chocolate; chopped |
| 2 | tb | Cornstarch dissolved in 1 tablespoon cold water |
| 1/4 | ts | Salt |
| 1 | ts | Vanilla extract |
| 2 | tb | Unsalted butter |
| | FROSTING |
| 12 | oz | Semisweet chocolate; chopped |
| 12 | tb | (1 1/2 sticks) unsalted butter |
| 1/2 | c | Hot water |
| 1 | tb | Light corn syrup |
| 1 | tb | Vanilla extract |
