Brownies

• Preheat the oven to 350°F. Lightly grease a 9 X 13-inch pan and line with parchment paper, leaving a 2-inch overhang. Grease the parchment, too.
• Place the butter and cocoa powder in at the top of a double-boiler. Cook over medium heat until the butter is melted. Add the chocolate and stir until melted and combined. Remove from the heat.
• Meanwhile, whisk together the flour and salt.
• In the bowl of a stand mixer fitter with the whisk attachment, combine the eggs, sugars, and vanilla, Whisk on low until combined. Increase the mixer speed to medium and slowly pour in the chocolate mixture down the side of the bowl. Continue to mix until the batter is smooth, about 1 minute.
• Stop the mixer and stir in the flour mixture until just combined.
• Pour the batter into the prepared pan and use an offset spatula to spread. Bake for 35 to 40 minutes, or until a toothpick inserted into the center of the pan comes out with a few moist crumbs. Allow brownies to cool in their pan on a wire rack before slicing. Sprinkle with flakey salt before serving, if desired. Some in an air-tight container at room temperature for up to 3 days.