Yes, you read that right: Peanut. Butter. Cup. Brownies. We’ve taken our favorite candy and sandwiched it in the king of chocolatey desserts. The result is a super gooey, salty-sweet brownie with pockets of creamy peanut butter. And guess what? You can make this beyond-simple recipe with your favorite store-bought mix. It’s that easy! We had the best results with the Ghirardelli Double Chocolate Brownie Mix and King Arthur Flour’s Gluten-Free Brownie Mix. Both mixes gave us incredibly fudgy brownies and yielded 9 hulking bars. If you’re feeling motivated, you can also make your own mix from scratch. We recommend this recipe from one of our favorites, Bistro Menil. This recipe makes a 9-inch square pan of brownies, so you might need a few extra peanut butter cups to make a complete layer.
Preheat the oven according to the package instructions (typically between 325°F and 350°F) and grease an 8-by-8-inch metal pan. For easy removal, line the pan with parchment paper, leaving a 2-inch overhang on two sides. Grease the parchment paper.
In a large bowl, prepare the brownie mix according to package instructions. Using a spatula, spread half of the brownie batter in the bottom of the pan. Arrange 9 of the peanut butter cups in the pan, then cut the remaining 3 in half and fit in along the edges. Scrape the remaining brownie batter into the pan and smooth the top. Sprinkle with flaky sea salt.
Bake the brownies until crisp around the edges and the middle is set, 35 to 45 minutes depending on the mix. Transfer the pan to a wire rack and let cool completely. Cut into 9 squares and serve.
If you’re feeling motivated, you can also make your own mix from scratch. We recommend this recipe from one of our favorites, Bistro Menil.
PRO TIP There is a lot of debate about glass versus metal pans for brownies. In our extensive testing, we’ve found that light colored metal pans deliver the best results. They conduct heat quickly and evenly, so your brownies will be evenly cooked throughout. Often with glass pans, it takes longer for the center of your brownies to cook. So, by the time the middle of your brownies are cooked through, the edges are already tall and, most likely, getting hard and over- cooked.
NOTE Please note that your box mix might call for oil, melted butter, water or eggs.
MAKE AHEAD The brownies can be stored in an airtight container for up to 2 days.