Oven-Baked 5-Ingredient Peanut Butter Cup Brownie Bars

These peanut butter cup brownie bars are an easy shortcut dessert made with just five ingredients. A boxed brownie mix creates a rich, chewy base, while mini peanut butter cups melt into the center for a classic chocolate-and-peanut-butter combination.

They’re simple enough for a weeknight treat and easy to serve at potlucks, family gatherings, bake sales, or movie nights. Enjoy them slightly warm with a glass of milk, coffee, or a scoop of vanilla ice cream.

 

Servings: 20 bars
Prep Time: 10 minutes
Cook Time: 30–35 minutes
Total Time: About 45 minutes

 

Ingredients

• 1 box family-size brownie mix for a 9×13-inch pan
• 2 large eggs
• 1/2 cup vegetable oil
• 1/4 cup water
• 20 to 24 mini peanut butter cups, unwrapped

 

Instructions

1. Prepare the oven: Preheat the oven to 350°F (175°C). Lightly grease a 9×13-inch glass baking dish or line it with parchment paper.
2. Make the batter: In a large bowl, combine the brownie mix, eggs, vegetable oil, and water. Stir until the batter is evenly mixed and thick.
3. Add the first layer: Spread about two-thirds of the brownie batter evenly into the prepared pan.
4. Add the peanut butter cups: Arrange the unwrapped mini peanut butter cups evenly over the brownie batter.
5. Cover with batter: Drop the remaining brownie batter over the peanut butter cups and gently spread it across the top. Some of the candy may remain visible.
6. Bake: Bake for 30–35 minutes, or until the center is set and a toothpick inserted into the brownie portion comes out with moist crumbs but no wet batter.
7. Cool and slice: Let the brownies cool completely before cutting. For cleaner slices, chill them for about 30 minutes before cutting into 20 bars.

 

Tips and Variations

• Choose your favorite brownie mix: Fudge, dark chocolate, or milk chocolate mixes can all work well. Use a box designed for a 9×13-inch pan.
• For cleaner cuts: Chill the cooled brownies before slicing and wipe the knife between cuts.
• Add flaky salt: A small sprinkle of flaky sea salt over the finished bars adds a salty contrast to the sweet chocolate and peanut butter.
• Add a peanut butter drizzle: Melt a few spoonfuls of peanut butter and drizzle it over the cooled brownies for an extra finishing touch.

 

Serving Suggestions

Serve these bars on their own or with vanilla ice cream. They also pair nicely with fresh strawberries, pretzels, or salted nuts when you’re putting together a dessert platter.

 

Storage

Store cooled brownie bars in an airtight container at room temperature for a few days, or refrigerate them if you prefer a firmer texture. They can also be chilled before serving for especially neat slices.

These peanut butter cup brownie bars are a simple way to turn a boxed brownie mix into a fun homemade-style dessert with very little preparation.