The Gooey Peanut Butter Brownies Everyone Will Love

There’s just something about the combination of chocolate and peanut butter that feels like pure magic to me. Whenever I’m craving a sweet treat that’s both comforting and indulgent, these gooey peanut butter brownies are the first thing that comes to mind. They’re rich, fudgy, and have that perfect swirl of creamy peanut butter that makes every bite a little extra special. Honestly, if you’re a peanut butter lover like me, you’ll be hooked after the very first bite.

What I really love about this recipe is how simple it is to whip up. You don’t need a long list of fancy ingredients or hours in the kitchen — just a box of brownie mix, a few pantry staples, and of course, that glorious spoonful (or two) of peanut butter. In fact, I like to add an extra drizzle on top before baking because, well, there’s no such thing as too much peanut butter in my book. These brownies come out of the oven looking bakery-worthy, but they’re effortless enough to make on a busy weeknight.

These brownies are also perfect for sharing, though I’ll admit they disappear pretty quickly in my house. Whether you’re baking them for a potluck, a cozy weekend at home, or just because you need a little chocolatey pick-me-up, they’re always a crowd-pleaser. Cut them into big squares for an indulgent dessert, or into bite-sized pieces if you want them to stretch a little further (though fair warning, people tend to come back for seconds!). Either way, these gooey peanut butter brownies are the kind of treat that makes you look like a baking star with very little effort.

Ingredients

• 1 Box peanut butter brownie mix (any brand): The base of these brownies, making the recipe quick, easy, and perfectly chocolatey.

• 2–4 tbsp peanut butter (pouch was included with my cake box): Adds that creamy, nutty swirl that makes every bite irresistible.

• 1 egg: Helps bind the batter together for that fudgy brownie texture.

• 2 tbsp water: Keeps the brownies moist and smooth in the middle.

• 2 tbsp vegetable oil: Adds richness and gives the brownies that tender, chewy bite.

• 8×8 inch square tin: The perfect size pan for baking up thick, gooey brownies.

Recipe Instructions

You can find a printable recipe card at the bottom of this post.

1. Preheat your oven to 320°F (160°C).

2. Line a square baking tin with parchment paper, making sure the paper covers the bottom and sides for easy removal later.

3. In a mixing bowl, combine the cake mix with water, egg, and oil.

4. Use an electric mixer or whisk to blend the ingredients together until the batter is smooth and well combined.

5. Pour the batter evenly into the prepared baking tin.

6. Drizzle peanut butter over the top of the batter. You can add as little or as much as you like — I often add 2 extra spoonfuls to make the brownies extra creamy.

7. Place the tin in the preheated oven and bake for 15–18 minutes, or until a toothpick inserted into the center comes out clean.

8. Once baked, remove the brownies from the oven and let them cool completely on a wire rack.

9. After cooling, cut the brownies into small squares.

10. Serve and enjoy your delicious peanut butter brownies!

Tips & Tricks for Perfect Peanut Butter Brownies

• I always line my pan with parchment paper so the brownies lift out easily (and I don’t lose half the batch stuck to the tin).

• Don’t overbake! I like to pull mine out when they’re just set in the middle, they’ll keep cooking a little as they cool, which makes them extra gooey.

• If you want a really pretty swirl on top, use the tip of a butter knife to gently drag the peanut butter through the batter before baking.

• Feeling extra indulgent? Sprinkle a handful of chocolate chips or chopped peanut butter cups over the top before baking.

• Let them cool completely before cutting. I know it’s hard to wait, but it makes for much cleaner slices (and less sticking to the knife).

• I love cutting them into smaller squares if I’m serving a crowd. Though, let’s be honest, most people end up sneaking two anyway!

Serving

• I love serving these brownies warm with a scoop of vanilla ice cream. The gooey peanut butter swirl with melting ice cream is just dreamy.

• They’re just as good at room temperature, which makes them perfect for potlucks, bake sales, or packing into lunchboxes.

• For a little extra fun, drizzle some melted chocolate or caramel sauce over the top before serving.

• These brownies pair so well with a big glass of cold milk or a hot cup of coffee, it’s the ultimate treat for any time of day.

• If you’re feeling fancy, cut them into bite-sized squares and arrange them on a platter for a party spread. They always disappear fast!

Storing

• I usually keep these brownies in an airtight container at room temperature, and they stay fresh and fudgy for about 3–4 days.

• If you want them to last longer, pop them in the fridge, they’ll keep for up to a week (though mine never make it that long!).

• You can also freeze them! Just wrap each square in plastic wrap, place them in a freezer bag, and they’ll be good for up to 2 months.

• To enjoy frozen brownies, let them thaw at room temperature or give them a quick warm-up in the microwave for that just-baked taste.