Guinness Brownies

semisweet chocolate, cut into pieces

unsalted butter, at room temperature

whole wheat pastry flour (or substitute white whole wheat flour or all-purpose flour)

all-purpose flour

plus 1 tablespoon unsweetened cocoa powder

kosher salt

granulated sugar

large eggs, at room temperature

pure vanilla extract

plus 2 tablespoons Irish stout beer (such as Guinness), at room temperature with any foam skimmed off

semisweet chocolate chips

cup (1 stick) unsalted butter, at room temperature

powdered sugar

 teaspoon pure vanilla extract

–3 tablespoons Irish stout (such as Guinness)