From Baked: New Frontiers in Baking by Matt Lewis and Renato Poliafito

(sorry about the imperial measures, but you can figure them out!)

1 1/4 cups all-purpose flour
1 tsp salt
2 tbsp dark unsweetened cocoa powder
11 oz dark chocolate (60 to 72% cacao), coarsely chopped
8 oz unsalted butter, cut into 1-inch pieces
1 tsp instant espresso powder
1 1/2 cups granulated sugar
1/2 cup firmly packed light brown sugar
5 large eggs, at room temperature
2 tsp pure vanilla extract

Preheat the oven to 350ºF. Either butter a 9x13 pan or place parchment in the pan and butter (I used parchment so it would be easier to pull the whole thing out of the pan to slice the brownies).

In a bowl, combine the flour, salt, and cocoa powder.

In a glass bowl over a pan of simmering water, combine the chocolate, butter, and espresso powder. Stir until the butter and chocolate are melted and the mixture is smooth. Turn off the heat and add the sugars, mixing until fully combined.

Add 3 of the eggs and mix, then add the other two eggs and the vanilla and whisk until combined. Do not overbeat.

Fold the dry ingredients into the chocolate mixture with a rubber spatula until just combined, leave just a bit of flour visible.

Pour into the buttered pan and smooth. Bake for 30 minutes, rotating halfway through. It's done when a toothpick comes out mostly clean with a few crumbs. Cool completely (in tin) and then slice.

I usually refrigerate the brownies for a few hours before I slice the brownies, I find that makes it easier.