INGREDIENTS
1
Egg, large
1 3/8 cups
All-purpose flour, unbleached
1/2 tsp
Baking soda
6 oz
Bittersweet chocolate
1/2 cup
Brown sugar, packed dark
1
Confectioners' sugar
1/2 cup
Granulated sugar
1/2 tsp
Salt, fine
3/4 tsp
Vanilla extract, pure
1
unsalted butter (1 stick), unsalted