- 5 Tbsp unsalted butter, plus more for muffin tin
- 1 Tbsp all-purpose flour, plus more for dusting
- 14 oz semisweet chocolate, chopped
- 2 Tbsp sugar
- 2 large eggs
- ¼ tsp salt
Preheat oven to 375 F. Generously butter a standard 6-cup muffin tin. Dust with flour, tapping out excess; set aside. Put chocolate, butter, and 1 Tbsp sugar in a medium heat-proof bowl set over a pan of simmering water; whisk occasionally until smooth. Remove form heat, and let stand until cool and thickened, 3 to 5 minutes. Process eggs and remaining Tbsp sugar in a food processor until pale and doubled in volume, about 2 minutes. Sift flour and salt into egg mixture; pulse to combine. Add chocolate mixture ¼ cup at a time; pulse each addition until combined, about 10 times. (Batter will be thick.) Spoon mixture into the prepared muffin tin, filling cups three-quarters full; swirl tops with back of spoon. Bake until tops are springy to the touch, 18 to 20 minutes. Immediately turn out onto wire racks; reinvert, and let cool.