Serves 12
Softened butter, for pan
12 ounces bittersweet chocolate, broken up
11 tablespoons unsalted butter, cut up
¾ cup granulated sugar
5 eggs, separated
⅓ cup all-purpose flour
Chocolate glaze, optional (recipe follows)
1. Prep: Butter a 9-inch springform pan. Line with a round of parchment paper and butter the parchment. Heat oven to 350F.
2. Melt: Drop chocolate and butter into a large, microwave-safe mixing bowl. Zap to melt in two 1-minute intervals. Stir smooth. Set aside to cool down, about 10 minutes.
3. Mix: Whisk sugar into chocolate. Whisk yolks into chocolate. Whisk flour into chocolate.
4. Fluff: Beat egg whites to soft peaks.
5. Fold: Vigorously whisk one-third of the egg whites into the chocolate batter. Switch to a soft spatula. Gently but thoroughly fold in remaining whites.
6. Bake: Pour batter into the prepared pan. Bake until the cake is firm and springy, about 32-34 minutes. Cool completely on a rack before releasing cake and inverting it onto a cardboard round.
7. Glaze: Serve as is, perhaps with a sprinkle of powdered sugar. Or glaze: Set cake (on its round) on a rack. Set rack over a rimmed sheet pan to catch the drips. Pour all the warm glaze into a big puddle on top. Use an offset spatula to nudge the glaze toward the edges, where it can drip becomingly down the sides. Let set a few minutes. Stun guests.
Chocolate glaze
Chop 4 ounces semisweet chocolate and tumble it into a medium bowl. Heat ½ cup heavy cream to boiling. Pour hot cream over chocolate. Cover with a plate and let stand 5 minutes. Gently whisk smooth. Stir in 1 teaspoon cognac, if you like.
Provenance: Adapted from Patricia Wells’s masterpiece Bistro Cooking.