- 16 ounces good-quality semisweet chocolate
- 10 tablespoons unsalted butter
- 5 extra-large eggs
- Preheat oven to 375°F.
- Line the bottom of an 8 1/2-inch springform pan with parchment paper or aluminum foil. Coat inside of pan with nonstick cooking spray.
- Chop chocolate into pieces. Cut butter into small chunks. Place chocolate and butter in a double boiler or in a large metal bowl over simmering water, making sure bowl doesn't touch water. Melt, stirring frequently, until smooth. Remove from heat.
- Whisk eggs and a pinch of salt in bowl of an electric mixer, until mixture triples in volume, about 8 minutes. Fold chocolate mixture into egg mixture with a flexible rubber spatula until completely incorporated.
- Pour mixture into prepared pan. Bake for 20 minutes. The center will still be a little soft. Remove from oven. Let cool at least 30 minutes before cutting. The center will sink a little as it cools. You can refrigerate the cake for up to 2 days (let sit at room temperature for 1 hour before serving).