Next, I add the flour, cocoa powder, salt, and baking powder right on top of the wet mixture. I gently fold everything together until I see no streaks of flour. The batter will be thick, almost like chocolate frosting, and that’s exactly how it should be. The thickness helps cradle the peanut butter cups.
Then comes my favorite part: layering the peanut butter cups. I spread half the batter in the pan, pressing it gently into the corners. Then I lay the peanut butter cups in neat rows, almost covering the entire surface. When you look at it, it almost feels like you’re building a secret brownie treasure chest. I spread the remaining batter over the top, smoothing it carefully so the cups stay hidden.
As the brownies bake, the peanut butter cups soften and create the most delicious pocket of creamy filling. When they’re done, I always let them cool completely before slicing—if I rush, they fall apart because they’re so fudgy. But once they’re set, the layers slice beautifully into thick, indulgent squares.
Pro Tips for Best Results
The biggest discovery I made while testing this recipe is that the brownies turn out fudgier when you whisk the butter and sugar together really well before adding the eggs. It gives them that shiny, crackly top everyone loves. I tested skipping that step once, and the difference was noticeable—the top was dull, and the texture wasn’t as luscious.
Another tip: freeze the peanut butter cups for about 10–15 minutes before layering them in. This keeps them from melting too quickly in the oven and helps maintain that dreamy layered look when you cut the brownies. Warm peanut butter cups can disappear into the batter too quickly.
Don’t overbake these brownies. I repeat—don’t overbake them. For the fudgiest texture, I always pull them out when the center still looks slightly soft. They continue to set as they cool, and the result is perfection. Overbaking dries them out, and that’s heartbreaking when you’ve used an entire tray of Reese’s cups.
Finally, use a long, sharp knife to slice them and wipe it between each cut. It keeps the squares neat and preserves those gorgeous layers.
Common Mistakes to Avoid
One mistake I made early on was mixing the batter too aggressively after adding the flour. Once you add your dry ingredients, switch to a gentle fold. Overmixing activates the gluten in the flour, which leads to tough brownies instead of soft, fudgy ones.(See the next page below to continue…)