These are like little volcanoes that produce a flow of molten chocolate lava when you cut into them. The cake is surprisingly light and forms a nice contrast to the rich, gooey chocolate center. They cook so quickly—10 minutes—that they can be a “go to” dessert when you don’t have time but you want people to say “Wow!”
Cakes Yield 4
4 oz bittersweet chocolate, chopped (or ¾ cup of chips)
4 Tbsp butter, room temperature, plus more to butter the cups
¼ cup heavy cream
⅓ cup sugar
⅓ cup all-purpose flour
½ tsp vanilla extract
¼ tsp salt
Cocoa powder as needed for dusting the baking cups
½ cup heavy cream
1 Tbsp sugar
1 tsp instant espresso powder
Preheat oven to 425°
Place butter, and cream in a stainless steel bowl set over simmering water to serve as a double boiler. When the butter has melted, add the chocolate and remove from heat. Stir the chocolate into the mixture to melt it. Place back over the simmering water for a few seconds if it needs a little more heat. Remove from the heat and reserve.
Beat the sugar with the eggs and yolks on medium-high speed for 3 minutes, until lightened in color and fluffy. Turn the mixer to low speed. Add the flour and salt and mix until combined. Add the vanilla extract. By hand, fold in the melted chocolate until just combined.
Liberally butter each custard cup or ramekin. Dust the inside of each cup with cocoa powder. Sift the cocoa through a wire strainer. If you want to avoid a messy cleanup, do this over a couple of sheets of paper toweling.
Fill each cup about 3/4 full, leave a bit of room for expansion during baking. Place the cups on a baking sheet. Bake for 10 minutes. A skin will form on top, but they should still be soft in the middle.
Remove from oven and rest for 3 minutes. Invert each onto individual serving plates. The cakes should drop right out of the cups. Every now and then one of them won’t let go. If this happens turn it right side up, run a paring knife around the edge to loosen it and try again. They will be hot; use an oven mitt or towel to hold the cups. Use the point of a paring knife to lift the edge of the cup and remove.
Beat the heavy cream with the espresso powder and sugar to soft peaks. Serve with a dollop of the whipped cream next to the cake.