Extreme Peanut Butter Brownies

Make the Brownies: Preheat the oven to 350 °F, and grease the bottom and sides of a 9-inch square baking pan with butter or cooking spray. Melt the butter over low heat in a medium saucepan. As soon as it's melted, remove from heat and let cool for 3-4 minutes. Stir in the cocoa powder and sugar until combined. Gradually mix in the eggs and vanilla extract, until the batter is glossy. Combine the flour and salt, then slowly add them to the brownie batter, stirring just enough to combine. Pour half of the brownie batter into the 9-inch by 9-inch pan. Top the batter with a layer of Nutter Butter cookies. Warm peanut butter in the microwave for 20 seconds. Stir, then drizzle half atop Nutter Butters. Top with remaining batter. Plop spoonfuls of peanut butter onto the batter, then use a spoon to gently swirl the two together, creating a marbleized effect. Bake for 28-30 minutes, or until a toothpick inserted into the center of the brownie comes out with just a few crumbs (and maybe melted peanut butter—but not liquid brownie batter). Make the Peanut Butter Drizzle: Heat peanut butter in the microwave for 20 seconds, stirring to form a smooth sauce. Drizzle atop cooled brownies and top with chopped peanut butter cups.