"The balsamic vinegar is the key to getting a nice crust to this cake. Don't worry if you see the cake rise up, then fall and even develop a few cracks-- that's part of the recipe...."
INGREDIENTS
•
14 oz bittersweet chocolate, chopped
•
½ cup unsalted butter, cut into pieces
•
7 large large eggs, at room temperature and separated
•
1 Tbsp balsamic vinegar
•
½ cup + 2 Tbsp granulated sugar
•
1 tsp vanilla extract
•
½ tsp salt
•
Icing sugar, for dusting