This recipe from Alice Medrich (via The Amateur Gourmet) makes brownies that are crusty on the surface and chewy inside.

// Shopping List :

• 10 tablespoons (140 grams) unsalted butter,
• 1 1/4 cups (250 grams) sugar
• 3/4 cup plus 2 tablespoons (65 grams) unsweetened cocoa powder (natural or Dutch-process)
• 1/4 teaspoon salt
• 1/2 teaspoon pure vanilla extract
• 2 large eggs, cold
• 1/2 cup (65 grams) all-purpose flour
• 2/3 cup (75 grams) walnut or pecan pieces (optional)
• 8 x 8 inch  baking pan
• Parchment paper

// Instructions : The Amateur Gourmet