Every once in a while a dessert comes along that smacks you in the face. Here’s one. It’s a one-layer French-style gateau, not a layer cake, dark, rich chocolate but not oversweet. It’s from Clare Ptak, a Chez Panisse alum who’s now baking in London. The recipe came out of Milk Street Magazine. It results in an incredibly moist cake, rather gooey in the center. It’s the sort of recipe that takes several bowls and other equipment, but the dishwashing is a small price to pay for this deliciousness
Ptak’s techniques are a little different than expected, the yolks are beaten for a while before they’re introduced to the chocolate, and the whites are not whipped to stiff peaks – you want soft peaks that bend very gently.
I used Ghirardelli 70% Chocolate, which can be found in supermarkets and for the dark rum, used Rhum Barbancourt, which is Haitian. Do not let the prunes turn you off. They’re a respected ingredient in French cooking, and, finely chopped, add texture and a flavor note that’s hard to identify but fits beautifully with the other ingredients.
It looks quite plain. It’s possible to shower some powdered sugar over it; when I needed to dress it up, I’ve squiggled whipped cream around the base and tumbled fresh raspberries in the middle. (Yes, aerosol whipped cream, I confess. I was contributing it to a party where I didn’t have access to whip it myself.) Using it with this cake is a good example of how whipped cream can actually cut richness.
9 Tbs. salted butter (1 of the tablespoons should be softened)
8 oz. pitted prunes, about 1 ½ cups, finely chopped
1/3 c. dark rum
1 Tbs. molasses
12 oz. bittersweet chocolate, finely chopped
6 large eggs, separated
1/3 c. plus 1/4 c. white sugar
1/2 tsp. kosher salt
Preheat the oven to 325 degrees with a rack in the middle position. Use the softened butter to coat the bottom and sides of an 8- or 9-inch springform pan.
In a container that’s microwave safe, like a glass measuring cup, combine the prunes rum and molasses. Microwave until the rum is bubbling, 45 to 60 seconds. Let sit for at least 15 minutes, stirring occasionally.
Gently melt the butter and chocolate. I do it very slowly in a microwave, with short bursts of heat punctuated by stirring. When it gets to a certain point that there is melted chocolate and butter with some lumps swimming in it, you may stop microwaving and just stir until the lumps melt. Ptak talks about using a metal bowl set over a pan of simmering water, melting the butter and then stirring in the chocolate until it’s melted. When it’s smooth, set it aside and proceed with the egg yolks.
In a large bowl, whisk together the egg yolks and 1/3 cup of sugar until the mixture is pale and glossy. (This took me about a minute, but I whisk slowly; YMMV.) Slowly add the melted chocolate mixture and whisk until smooth. Stir in the prune mixture.
Using a stand mixer with the whisk attachment (okay, I admit, I used a hand mixer, slower but easier to control), whip the egg whites and salt on medium-high until the mixture is light and foamy, perhaps another minute. With the mixer running, slowly sprinkle in the remaining ¼ cup of sugar and continue to whip until the whites are thick and glossy and hold those soft, bendy peaks. Don’t hesitate to stop and check; overbeating to the stiff-peak point doesn’t ruin it, but the texture won’t be as tender.
Whisk about a third of the whipped egg whites into the chocolate mixture to lighten it. It doesn’t have to be perfectly mixed. Gently fold in the remaining whites, using a rubber spatula, until the batter is marbled but not quite fully blended.
Pour the batter into the prepared pan. Smooth the top with a spatula if needed. Bake until the edges of the cake are firm and cracked, 35-40 minutes for the 9-inch pan, 40-45 minutes for the 8-inch pan. The center will be just set – but will jiggle if you shake the pan gently.
Cool the cake in the pan on a wire rack for at least 1 hour before serving. It will sink as it cools.
So rich it serves 12.