Heat the oven to 350 F. Butter a 9-by-13-inch baking pan and line it with buttered parchment paper. Credit: Diana Rattray
Combine the butter, chocolate, and sugars in a medium saucepan and place it over low heat. Cook, stirring, until the butter and chocolate have melted and the mixture is smooth. Remove the mixture from the heat and let it cool a bit. Credit: Diana Rattray
In a mixing bowl, whisk the eggs with the salt and vanilla. Add the chocolate mixture and whisk to blend. Fold the flour into the batter until well combined, then fold in the nuts. Spread the mixture in the prepared baking pan. Credit: Diana Rattray
Bake for 30 to 40 minutes or until the top is shiny and slightly crackled. Credit: Diana Rattray
Cool in the pan on a cooling rack. Slice and enjoy! Credit: Diana Rattray