10 Underrated Mix-Ins That Effortlessly Upgrade Boxed Brownies

Sometimes you want a batch of fudgy homemade brownies without spending time measuring out ingredients, and that's where boxed brownies come in. These convenient dry mixes typically require the addition of a few pantry staples like eggs and oil before everything is stirred together, ready for baking. But while a box mix makes whipping up a batch of chocolatey treats wonderfully fuss-free, you don't necessarily have to stick to the instructions on the packaging.

With a few simple mix-ins, you can easily transform a basic boxed brownie into something that feels decidedly bakery-worthy. Chocolate chips and nuts are, of course, classic choices for enhancing the batter, but there are plenty of other additions to consider. Whether you're looking to add crunch or creaminess, amp up the sweetness, or introduce a hint of warmth, there's an ingredient that can help. From everyday staples to unexpected flavor-boosters, these underrated mix-ins are sure to give your next batch of brownies a delicious twist.

With a simple scattering of pretzels, you can add an irresistible sweet-and-salty crunch to every bite of your boxed brownies. Mini pretzel twists or sticks will work great here, and these can either be left whole or lightly crushed into smaller pieces for a more even distribution throughout the batter. You'll fold the pretzels through the batter right before transferring everything to the baking pan, so the prep still remains incredibly straightforward. 

The result is a batch of ultra-decadent brownies with heaps of visual appeal and a moreish textural contrast. The combination of the rich, fudgy brownie base and crisp, golden pretzels is surprisingly satisfying, and feels a little lighter than your average nut-studded brownie. Plus, pretzels pair beautifully with a whole host of other mix-ins. To continue the swalty flavor theme, try throwing in some butterscotch chips alongside the pretzel bits, and finishing the brownies with a sprinkle of flaky sea salt.

Adding espresso powder to brownies is a popular way to boost the chocolatey depth, but there's another, often overlooked ingredient that also works to lift the chocolate flavor — cayenne pepper. By adding a pinch of this spice cupboard staple to your box mix batter, you'll subtly elevate your brownies, all without actually making them too spicy. 

Cayenne pepper contains a compound called capsaicin, which pairs nicely with the rich cocoa notes. This means the spice is a highly effective tool for creating a more complex flavor profile, and adding just enough warmth to complement the chocolate without overpowering it.

A quarter teaspoon of cayenne pepper is enough to give your brownies a boost, and this can be whisked into the dry box mix blend before you add the wet ingredients. If you'd prefer a more noticeable spicy kick, increase the quantity as desired. Or, you could build on the cayenne pepper's warmth by combining it with other spices like cinnamon and chili powder, for a Mexican-inspired flavor.

Candied ginger is often used as a decorative finishing touch in bakes and cocktails, but this sweet, chewy ingredient also works amazingly well in brownies. Not only does this underrated mix-in introduce a pleasant peppery warmth, but it brings pops of chewiness too, making your brownies more texturally interesting and sophisticated.

Whether you're reaching for a store-bought candied ginger or making your own from scratch, just chop the golden chunks finely, and scatter them into the batter as the final step. You could absolutely whisk some ground ginger into the dry ingredient blend too, if you want that warming ginger flavor to be even more pronounced. 

Chocolate and candied ginger pair together brilliantly, with the lively, sweet heat of the aromatic mix-in contrasting the sweet, velvety richness of the cocoa especially well. The crystallized ginger pieces also keep the batter from feeling overly heavy by brightening up every bite.

Another overlooked way to take boxed brownies to the next level is by combining the batter with sweet, custardy banana pudding. This is exactly what we do in our delightfully gooey banana pudding brownie recipe, which most definitely proves that the beloved instant pudding is more than just a shortcut dessert. Swirling it into your batter creates a luscious texture and a distinct banana flavor that pairs fantastically with the rich chocolate. It also gives your brownies an eye-catching marbled finish with very little extra effort.

The best approach is to mix the banana pudding with cream cheese, egg, and milk until thick and smooth. Then you can add alternating dollops of the brownie batter and pudding mixture to a baking pan, and lightly swirl the two together with a skewer. Once baked, the brownies will come out with a gloriously fudgy chocolate base and pockets of creamy banana goodness — a match made in heaven if you ask us.

Butterscotch chips might feel more at home in cookies or blondies, but these golden morsels are a must-try brownie mix-in. They're ready to add to the batter straight from the package, so they'll fit seamlessly into the fuss-free approach of boxed brownie mix. As they bake, the chips soften into little pockets of buttery, caramel-like sweetness, giving the brownies an extra layer of indulgence.

Butterscotch chips can be used much like chocolate chips. Just mix up the brownie batter as instructed on the packaging, and fold the chips in as the final step. Feel free to sprinkle a few more over the top before you pop the pan in the oven. Butterscotch chips also work great alongside crunchy mix-ins (think chopped pecans or walnuts, pretzel pieces, or crumbled cookies). And to deepen the caramel notes further, you could also drizzle some butterscotch sauce or dulce de leche over the brownies post-baking once they've completely cooled. 

Miso paste is a go-to for crafting savory soups, sauces, and dressings, but this umami-rich flavor-booster is more versatile than you'd think. In sweet recipes like brownies, a small spoonful of miso can add a subtle saltiness that balances the sweetness beautifully. Miso's distinct tang also complements the bitterness of the cocoa, building depth and giving the brownies a well-rounded flavor profile.

White miso, which leans slightly sweeter and milder than other varieties of miso, is generally the best option for enhancing brownies. Just add the paste to the boxed mix along with the other wet ingredients before mixing everything together thoroughly. It's a mix-in that requires hardly any extra effort, but can be truly transformative.

To really go all out with the miso experience, there's also the option to finish the baked and cooled brownies with a luscious miso salted caramel. Make a basic salted caramel sauce with butter, sugar, and heavy cream, then stir in a spoonful of miso at the end, and you'll have a gloriously sweet and salty brownie topping that amps up the sophistication factor no end.

With its silky consistency, nutty taste, and array of health benefits, tahini can make a batch of basic boxed brownies feel extra special. This creamy sesame paste blends seamlessly with the brownie batter, bringing richness, complexity, and swirls of contrasting color. Tahini may be underrated, but it makes for an excellent alternative to peanut butter if you need to keep your brownies nut-free.

Tahini can easily be dolloped over the brownie batter in the baking pan, and lightly swirled with a skewer or knife to create a striking marbled effect. The resulting bake will have an extra gooey crumb and a delicate nutty taste that enhances the chocolate without overpowering it. Plus, you'll get a welcome dose of protein, healthy fats, and antioxidants. When the brownies are fresh out of the oven, a final sprinkling of sesame seeds or flaky sea salt would also go down a treat. Or, you could serve the brownies up with a generous scoop of tahini ice cream.

Chocolate and raspberry are an irresistible match, especially in brownie format. The sweet-tart tang of the berries cuts through the rich cacao, imparting a bright, fruity contrast that prevents heaviness. And you don't have to make brownies from scratch to enjoy this classic pairing. Incorporate the raspberries into a boxed brownie batter, but freeze-dried varieties are by far the best (and sometimes forgotten) option.

Because the berries have been dehydrated, they offer a much more concentrated flavor than their fresh or frozen counterparts. Additionally, freeze-dried raspberries won't add any extra moisture to the brownie batter, so there's no risk of textural issues or increased baking times. Instead, you'll have a perfectly fudgy, chocolatey batch that's studded with bursts of vibrant raspberry flavor.

Freeze-dried raspberries can be added whole or crushed into smaller pieces for a more uniform spread throughout the batter. Fold them in once you've mixed everything per the package instructions, and reserve some extra berries for scattering over the baked brownies later if desired.

With espresso powder being such a popular brownie mix-in, chocolate-covered espresso beans are a natural next step, though frequently overlooked. These flavor-packed morsels deliver a double hit of coffee and chocolate, and their satisfying crunchy texture provides a welcome contrast to the fudgy crumb. Like espresso powder, the coffee beans work to intensify the cocoa notes and deliver more pronounced bursts of that bold espresso flavor. The chocolate coating adds another element of sweetness and indulgence, mellowing any bitterness and creating a deliciously balanced brownie.

Chocolate-covered espresso beans come in milk, dark, and white varieties, and they're available at many major grocery chains like Trader Joe's and Costco. Whether you're stirring them into the batter or sprinkling them on top before the brownies hit the oven, the beans couldn't be easier to incorporate. Feel free to also throw in some semi-sweet chocolate chips or chopped nuts, and you could enhance the batter with a sprinkle of espresso powder, too.

We often see walnuts or pecans added to brownie batters, but pistachios are an underrated mix-in that'll have you wondering why you didn't try them sooner. Pistachios bring a satisfying crunch, as well as a distinctly earthy, buttery, and slightly sweet flavor that tastes wonderful alongside chocolate. They look great too, adding attractive pops of green to the otherwise dark brownie base.

Roughly chop a handful of shelled pistachios, and fold these into your box mix batter for a straightforward yet game-changing upgrade. For an even more indulgent twist, try combining the nuts with white chocolate chips. You'll find that the creamy sweetness works particularly well with the pistachio's distinctive nuttiness.

If you'd prefer to add pistachio flavor without the crunch, try using pistachio cream instead. This silky spread is ideal for swirling through the unbaked batter, or melting and drizzling over the brownies before serving.