Ingredients

• cooking spray with flour
• 1 cup all-purpose flour
• 3/4 cup dark cocoa powder (such as Hershey's® Special Dark)
• 1/4 teaspoon salt
• 8 ounces bittersweet chocolate (such as Ghirardelli®), chopped
• 3/4 cup white chocolate chips (such as Ghirardelli®)
• 6 tablespoons butter at room temperature, cut into cubes
• 1 cup white sugar
• 4 eggs, room temperature
• 1 1/4 cups Irish stout beer (such as Guinness® Extra Stout), room temperature and foam skimmed off
• 1/2 cup chopped pecans (optional)
• 1 cup semisweet chocolate chips (such as Nestle® Toll House®)
• 1 tablespoon sifted confectioners' sugar, or as needed

Instructions

1. Place oven rack in the center position. Preheat oven to 350 degrees F (175 degrees C). Spray a 9x13-inch baking dish with cooking spray.
2. Whisk flour, cocoa powder, and salt together in a bowl.
3. Melt bittersweet chocolate, white chocolate chips, and butter in the top of a double boiler over simmering water, stirring frequently and scraping down the sides with a rubber spatula to avoid scorching. Remove from heat.
4. Beat white sugar and eggs together in a large bowl with an electric mixer until light and fluffy, about 3 minutes. Slowly add melted chocolate mixture and beat until just combined. Add flour mixture, 2 to 3 tablespoons at a time, until just combined. Whisk in beer until batter is thin; fold in pecans.
5. Pour batter into the prepared baking dish; sprinkle semisweet chocolate chips over batter.
6. Bake in the preheated oven until a toothpick inserted in the center of the brownies comes out with moist crumbs, 25 to 30 minutes. Cool to room temperature; dust top with confectioners' sugar.