The Quick Trick for Picture-Perfect Brownie Swirls

A 10-minute trip to the freezer is the secret to achieving a defined peanut butter ripple.
Peanut butter being swirled onto a baking tray of brownie batter.
Photo by Isa Zapata, Prop Styling by Christina Allen, Food Styling by Emilie Fosnocht

After countless fruitless attempts at developing a recipe for picturesque peanut butter swirl brownies, I was starting to become hopeless. No matter how delicious the brownies came out or how easy they were to make, the peanut butter swirl on top would always sink to the bottom. Every. Single. Time.

I tried adding powdered sugar into the mix, tried melting the peanut butter, and even attempted to thicken it with flour, but nothing prevented it from disappearing under the surface of the glossy chocolate batter. As a last-ditch effort (and culinary equivalent of a Hail Mary), I tried freezing the brownie batter right in the pan for 10 minutes before swirling the peanut butter on top and baking. Lo and behold, the peanut butter stayed afloat, and the brownies came out of the oven with a defined, painterly swirl; an undeniable success.

So why does freezing the brownie batter prevent the peanut butter from sinking? It’s all thanks to the melted chocolate and butter in the brownie batter: the two main ingredients that make up the bulk of the recipe. Once melted they are combined with whipped eggs and a touch of flour to create a smooth, free-flowing batter. When warm, the batter is relatively loose, which makes it unable to carry the weight of peanut butter on top. But when you pop the batter in the freezer for 10 minutes, the butter and chocolate firm up to create a slightly more solidified texture than can support the peanut butter swirl. It’s a simple technique you can use to add carefree peanut butter zigzags to any brownie batter that is made with melted chocolate and butter.

Photo by Isa Zapata, Prop Styling by Christina Allen, Food Styling by Emilie Fosnocht

In the process of testing, I learned a few tips that’ll get you the ultimate swirl: While you can easily dollop the peanut butter on top of the batter and zhuzh it around using a thin knife, I found that the most beautiful swirls are created by piping the peanut butter out of a small baggie with the corner cut off. Just pipe the peanut butter in organic, abstract squiggles (not unlike a Keith Haring piece), and then use a thin knife or toothpick to quickly drag through the spirals to create wispy, thin streaks. The real trick here is to practice restraint: As soon as you’ve achieved a few dramatic swirls, stop fussing. Over-swirling the peanut butter can result in a less striking presentation and sacrifice the joy of getting a generous, contrasting pop of peanut butter in each bite.

So as soon as the peanut butter has swirled evenly enough to get a bit in each brownie, pop it in the oven. After baking, allow the brownies to cool for at least an hour, preferably two, so the peanut butter has time to cool off and firm up before you cut into them. The extra wait time might feel tortuous, but cutting into hot-from-the-oven peanut butter is a recipe for disaster. Sit tight as it firms up enough to prevent a gloopy mess.

If you bake not only for taste but for beauty, this technique is for you. The brownies’ Van Gogh-ian Starry Night swirls are made to be shared online (and in person); all thanks to a quick trip to the freezer. So swirl (and freeze!) away, allowing your inner artist to come alive.