Death-by-Chocolate Cake "L’assassin"

To my mind, this is the ultimate in chocolate cakes. The secret of its molten core, despite the lengthy baking time, lies in the proportions I’ve devised for this scrumptious and indulgent cake. Its originality lies in the way I sweeten the cake, namely with a salted butter caramel instead of plain sugar.

The idea for the cake came to me while I was dozing one day. The brainwave sent me immediately to the kitchen to see how to put it into practice. The result exceeded my hopes and for once, I got it right on my first attempt.

Here is my assassin, crisp on the outside and rich, dense, and creamy on the inside.

Makes one 6-inch (15-cm) cake, to serve 4 to 6

Preparation time: 25 minutes

Cooking time: 45 minutes

Chilling time: 12 hours or overnight

Ingredients

• 3/4 cup (6 1⁄3 oz./180 g) beaten eggs (about 3 eggs)
• 1 tablespoon (1⁄3 oz./10 g) all-purpose flour
• 1 1/4 cups (9 oz./250 g) sugar
• 3–3 ½ tablespoons (50 ml) water
• 1 1/4 sticks. (5 oz./150 g) salted butter, room temperature, diced
• 4 oz. (125 g) bittersweet chocolate, at least 60 percent cacao

Preheat the oven to 295°F (145°C). Line the base and sides of a 6-inch (15-cm) springform pan with parchment paper. (Cut out a disc the size of the base, and a strip the length of the circumference and the width of the rim.)

With an electric beater, whisk the eggs and flour for 5 minutes, until very foamy. 

Transfer the mixture to the bowl of a stand mixer fitted with a whisk attachment, where you’ll need it to combine with the caramel a little later.

Place the sugar in a heavy saucepan over medium heat with just enough water to soak it, about 3 to 3 ½ tablespoons (50 ml). Ensure that there is no sugar on the sides of the saucepan, because this might cause all the caramel to crystallize again. 

Do not stir or move the pan until the syrup boils.

Cook until the caramel is a rich amber color.

Remove from the heat.

Very gradually add the diced butter and mix to incorporate. With each addition, the caramel cools a little and absorbs the water contained in the butter. 

What we want is for the water to evaporate. Initially, the caramel will sizzle with each addition, but this soon subsides.

As soon as all the butter has been incorporated, set the stand mixer to minimum speed and drizzle in the salted butter caramel until well combined.

Melt the chocolate over a hot water bath or in short bursts in the microwave oven, stirring after each burst. Pour it into the caramel mixture and whisk briefly until combined.

Scrape the batter into the pan and smooth the top. 

Bake for 45 minutes—it rises astonishingly high. 

To test for doneness, gently move the pan back and forth to see how the batter reacts. It should wobble a little in the center, without appearing liquid, like a jam that is setting. As it cools, it will return to its original depth.

Put the pan on a rack and let cool to room temperature. 

Then refrigerate the cake for 12 hours or overnight before turning it out. Bring it to room temperature for at least 20 minutes before serving in thin slices.

If you want to make a larger cake, refer to the coefficients below. Simply multiply each ingredient by the coefficient that corresponds to the pan. For example, for a 7-inch pan, multiply each ingredient by 1.36. Of course, round up or down to the easiest figure to weigh. However, you’ll need to increase the baking time, which depends partly on your oven. Do not remove until the cake has risen well and a crust has formed.