From Food & Wine by way of Dana Treat comes the easiest way to get all the best parts of the molten chocolate cake with none of the stress.
For this cake, you make a standard batter from melted butter, chocolate, sugar, and eggs, then pour most of it into a springform pan and bake for 25 minutes. That right there is good enough to serve on its own, but the real hoorah comes when you then take the reserved batter, spread it over the top of the cake, and give it an additional 15 minutes in a higher temperature oven, until it's just barely baked.
The result is a firm, dense bottom—the chewy, feels-like-food element that many flourless chocolate cakes lack—that acts as a crust-like container for the melting, pudding-like top. Nothing will break or burst or turn to goo or go terribly wrong. Success is (practically) guaranteed. And when you put it in the refrigerator, the bottom layer will become brownie-like, the top like mousse.
Preheat the oven to 350° F. Butter a 9-inch springform pan and line the bottom with parchment paper. Butter the paper.
In a large saucepan over low heat, melt the chopped chocolate and the butter. Add the cocoa powder and a pinch of salt whisk until smooth.
In the bowl of a stand mixer or in a medium bowl using an electric mixer, beat the egg yolks with 2/3 cup of the sugar until pale and light, about 3 minutes. Set aside.
In another bowl, using clean beaters, beat the egg whites until soft peaks form. Gradually add the remaining 2/3 cup of sugar and beat until the whites are firm and glossy.
Fold the chocolate into the egg yolk mixture until barely combined. Fold in the egg whites just until no white streaks remain.
Spoon 2 cups of the batter into a medium bowl and refrigerate—this will become your ooey-gooey topping.
Scrape the remaining batter into the prepared pan and smooth the top with a spatula. Bake for 25 minutes, or until the cake is puffed and a toothpick inserted in the center comes out clean.
Cool the cake completely on a wire rack. Don't panic if the sides of your cake has pulled away from the pan and the center is a bit sunken. This is a crater into which you will pull the reserved batter, after all. At this point, you can cover the cake and refrigerate for up to 2 days.
Remove the belt/girdle of the completely cool springform pan and spread the reserved cake batter over the top of the cake (it will be thick, so be gentle), leaving a 1-inch border around the edge. Refrigerate the cake for at least 1 hour.
Preheat the oven to 400° F. Bake the cake for 10 to 15 minutes, or until a thin crust forms on top and the batter is soft and creamy beneath the crust.
Let the cake cool for 10 minutes, then cut into wedges and serve warm. To store, cover the cooled cake in plastic wrap and keep in the refrigerator for up to 3 days. The pudding-like top will become delightfully mousse-y.
A (former) student of English, a lover of raisins, a user of comma splices. My spirit animal is an eggplant. I'm probably the person who picked all of the cookie dough out of the cookie dough ice cream. For that, I'm sorry.