Step 1

Preheat the oven to 350 degrees F.

Step 2

Set a kettle of water to boil.

Step 3

Butter a shallow 2-quart baking dish and coat it with the extra granulated sugar, tapping out the excess.

Step 4

In a large bowl, whisk the egg yolks with 1/2 cup of the granulated sugar until lightened in color.

Step 5

Slowly whisk in the melted chocolate a little at a time to prevent the eggs from scrambling.

Step 6

In a large, clean bowl, using an electric mixer on high, beat the egg whites and the salt together until soft peaks form.

Step 7

Whisk 1/3 of the egg white mixture into the chocolate mixture.

Step 8

Add the remaining egg white mixture into the chocolate mixture by gently folding them in with a rubber spatula until just combined, being careful not to overmix.

Step 9

Transfer the batter to the prepared baking dish.

Step 10

Set the dish in a roasting pan and pour enough of the boiling water into the roasting pan to come up about 1-inch up the outside of the baking dish.

Step 11

Bake until puffed and just set, with the center just barely moving when jiggled, about 25-35 minutes.

Step 12

Let cool for 5 minutes.

Step 13

Dust with the confectioners' sugar and serve.