Stout Sachertorte

STEP 1: MAKE THE PASTRY CREAM

Heat the milk and vanilla in a saucepan until steaming. In a bowl, whisk the egg yolks, sugar and cornstarch until pale. Whisk the hot milk into the yolks in a thin stream, return everything to the pan and cook over medium heat, whisking constantly, until thick and it has bubbled for 1 minute. Off the heat, whisk in the butter. Transfer to a bowl, press plastic wrap onto the surface and chill until cold, at least 1 hour 30 minutes.

STEP 2: MAKE THE APRICOT COMPOTE

Simmer the dried apricots, water, sugar and lemon juice, covered, until the apricots are very soft, about 15 minutes. Uncover and cook until thick and jammy, 3–5 minutes more. Pulse half the compote in a food processor until smooth and stir it back into the rest, so it spreads easily but keeps some texture. Cool completely. You should have about 1½ cups.

STEP 3: MAKE THE APRICOT GLAZE

Bring the apricot jam, water and lemon juice to a boil, then press through a fine-mesh sieve. Keep warm.

STEP 4: MAKE THE SPONGE BATTER

Heat the oven to 325°F. Grease three 8-inch round cake pans with butter and line the bases with parchment paper. Warm the stout and cubed butter in a large saucepan over low heat until the butter melts. Take off the heat and whisk in the cocoa powder and sugar. Whisk the sour cream, eggs and vanilla extract together, then whisk into the stout mixture. Sift the flour, baking soda, baking powder and salt together twice, then whisk into the wet mixture until just smooth. The batter will be thin.

STEP 5: BAKE THE SPONGES

Divide the batter equally among the pans. Bake for 20–25 minutes, checking at 20 minutes, until the center reads 200–205°F on an instant-read thermometer or a skewer comes out with a few moist crumbs. Cool for 10 minutes in the pans, then turn out onto wire racks and cool completely, at least 1 hour.

STEP 6: LAYER THE CAKE

Level the sponges if domed. Brush the top of the first sponge generously with warm apricot glaze using a pastry brush and let it soak in for a minute. Spread with half the compote to within ¼ inch of the edge. Brush the second sponge with glaze on both sides, set it on top and spread with the remaining compote. Top with the third sponge, base side up.

STEP 7: GLAZE THE OUTSIDE

Rewarm the remaining glaze if it has thickened. Brush the top and sides of the cake with a thin, even coat. Chill for 30 minutes, until the glaze is tacky and set.

STEP 8: MAKE THE GANACHE

Bring the heavy cream and light corn syrup just to a simmer and pour over the chopped chocolate in a heatproof bowl. Rest for 2 minutes, then stir gently from the center out until smooth. Stir in the softened butter, taking care not to whisk in air bubbles. Cool to 90–95°F.

STEP 9: POUR THE GANACHE

Set the cake on a wire rack over a rimmed baking sheet. Pour the ganache over the center in one go, letting it run down the sides. Make only one or two passes of an offset spatula across the top so it stays glossy. Let set at room temperature for at least 1 hour. Do not refrigerate once poured, or the shine will dull.

STEP 10: FINISH THE CRÈME DIPLOMAT

Whisk the cold pastry cream until smooth. In a stand mixer, whip the cold heavy cream to soft peaks, then fold it into the pastry cream in two additions, stopping as soon as no streaks remain.

STEP 11: SERVE

Slice the cake with a hot, dry knife and serve each slice with a spoonful of crème diplomat alongside.