A good Sacher torte, I admit, can be a bit of a beast to mix. I can’t do much to simplify that. However you’ll be relieved to know that I’ve simplified the assembly somewhat with a streamlined cook-and-pour glaze, which should help. Is it completely authentic? Maybe not, but the end result is excellent.
For the sponge cake:
5 ½ ounces bittersweet chocolate
5 ½ ounces butter
7 ounces (1 cup) sugar
2 ½ teaspoons vanilla extract
5 ounces (9) egg yolks
1 ¾ ounces (1) whole egg
7 ounces (7) egg whites
5 ½ ounces cake flour, sifted
apricot jam, processed until smooth in a food processor
For the glaze:
7 ounces sugar
3 ounces water
6.5 ounces bittersweet chocolate
For the sponge cake:
Prepare a 10-inch springform pan by lining it with parchment paper and spraying with cooking spray (see How to Prepare a Cake Pan for Baking under the Techniques menu). Preheat the oven to 325 and position a rack on the lowest shelf. Next, melt the chocolate in the microwave by zapping it with 5-6 10-second bursts (stirring in between). Let cool until just warm but still flowing.
In the bowl of a stand mixer fitted with the paddle, beat the butter with ¼ cup of the sugar on medium-high until light in color. Switch to the whip and add the egg yolks one at a time, scraping the bowl every now and again. Add the whole egg and whip until incorporated. With the machine on low, add the chocolate in a stream. Beat on medium-high until the mixture resembles chocolate buttercream.
Transfer the chocolate mixture to a large bowl, then wash and dry the mixer bowl. Affix the whip and whip the egg whites until foamy, not quite to soft peaks. Then, with the machine running, add in the sugar. Beat to soft peaks, the meringue will be sleek and glossy.
Gently fold 1/3 of the meringue into the chocolate mixture until almost incorporated. Sprinkle on several spoonfuls of the flour and fold some more, alternating with more meringue until both are completely incorporated. Pour the batter into your prepared pan.
Put the pan into the oven and prop the door open with a wooden spoon for 15 minutes (this will help the top rise evenly). Remove the spoon and close the oven door. Bake for 35-45 minutes more, until the top springs back when patted gently. Remove from the oven and cool on a wire rack in the pan. The cake will keep at room temperature overnight, uncovered, if you’d like.
When ready to assemble the torte, slice the cake horizontally into two layers. Spread the bottom layer with jam and replace the top layer (if it’s too thick to spread, heat it on the stove or in a microwave until to flows easily). Cover the entire torte with a thin layer of jam. Let sit until the jam has firmed, about half an hour.
Meanwhile, prepare the glaze.
In a heavy-bottomed 1-to-2-quart saucepan (any larger and there’ll be too much evaporation) bring the sugar and water to the boil. Add the chocolate and boil over medium-high heat, stirring occasionally, until the glaze reaches 234°F. Remove the glaze from the heat and allow it to cool, again, stirring occasionally. Let the glaze cool to below 150 before using it. The temperature isn’t terribly important so long as the glaze is warm and flowing when you use it. This will take up to half an hour.
Place the torte on a wire rack and pour the glaze over, evening out bald patches with an icing spatula. Allow to cool for about 15 minutes, then transfer to a serving platter. Allow to set up for at least 4 hours, preferably overnight. Torte will keep up to five days.
Slice the torte with a sharp knife dipped in hot water. Serve with a generous dollop of lightly sweetened whipped cream.