From Baking: From My Home to Yours by Dorrie Greenspan

Ingredients

1/4 cup all-purpose flour
1/2 teaspoon ground cinnamon (optional)
1/4 teaspoon salt
1 stick (8 tablespoons) unsalted butter, cut into 8 pieces
1/2 cup unsweetened cocoa powder
2 teaspoons finely ground instant coffee
2 large eggs, preferably at room temperature
1 cup sugar
1 teaspoon pure vanilla extract
1 cup broken or chopped walnuts or pecans
4 ounces bittersweet chocolate, coarsely chopped

Getting Ready:

Center a rack in the oven and preheat the oven to 325 degrees F.
Butter an 8-inch square baking pan and line the bottom with parchment or wax paper. Butter the paper, dust the inside of the pan with flour and tap out the excess. Place the pan on a baking sheet.
Whisk the flour, cinnamon, if you’re using it, and salt together.
Put the butter in a medium heavy-bottomed saucepan and place the pan over low heat. When the butter starts to melt, sift the cocoa over it and add the instant coffee. Continue to cook, stirring, until the butter is melted and the cocoa and coffee are blended into it. Remove from the heat and cool for about 3 minutes.
Using a whisk or a rubber spatula, beat the eggs into the saucepan one at a time. Next, stir in the sugar and vanilla (don’t beat anything too vigorously — you don’t want to add air to the batter), followed by the dry ingredients, nuts and chopped chocolate. Scrape the batter into the pan.
Bake for 30 minutes, at which point the brownies will still be gooey but the top will have a dry papery crust. Transfer the pan to a rack and let the brownies cool for at least 30 minutes. (You can wait longer, if you’d like.) Turn the brownies out onto a rack, peel away the paper and invert onto a cutting board. Cool completely before cutting into 16 squares, each roughly 2 inches on a side.