Fluffernutter Brownies

Fluffernutter brownies are an impossibly ooey-gooey treat. The rich and fudgy batter features two kinds of chocolate, plus mini marshmallows hidden inside. The very best part, though, is what makes these brownies taste like a Fluffernutter sandwich: the topping of swirled peanut butter and marshmallow creme.

For the uninitiated, the original Fluffernutter sandwich is a classic New England treat made by spreading creamy peanut butter and marshmallow creme between two slices of white bread. Marshmallow Fluff–brand marshmallow creme is made in Massachusetts, which is why all the kids in the Northeast grew up eating this sublimely sweet and sticky sandwich. But you can use any marshmallow creme for these brownies. They all tastes the same in this chocolatey dessert (and on your hands, fingers, cheeks—all the places where you’ll undoubtedly find it later!).

Ingredients for Fluffernutter Brownies

• Marshmallow creme: You can’t make a Fluffernutter without marshmallow creme, but to make a true Fluffernutter, use the Marshmallow Fluff brand. There are dozens of recipes you can make with marshmallow creme if you have some leftover.
• Miniature marshmallows: Yes, that’s two kinds of marshmallows! Mini marshmallows are stirred into the batter and stay suspended in the baked brownies.
• Peanut butter: Swirl creamy peanut butter into the batter. The best peanut butters for baking are commercially made ones like Jif or Skippy. Natural peanut butter separates and has a less stable texture.
• Butter: Use any of the best butter brands for baking. There’s no need to soften your butter first, since it gets melted in the microwave.
• Brown sugar: Brown sugar sweetens the brownies and adds caramel and molasses notes.
• Flour: All-purpose flour is classic for brownies. Remove any lumps by sifting the flour with a fine-mesh strainer.
• Chocolate chips: These brownies are extra decadent with two kinds of chocolate chips. Semisweet chips are melted into the batter, and dark chocolate chips are stirred in whole.
• Eggs: Always use room-temperature eggs in baking recipes. They blend in more smoothly, resulting in more consistent batter.
• Vanilla extract: The best vanilla extracts should be fragrant, with no chemical or artificial smell. You can always use homemade vanilla extract if you have it.
• Baking powder: It’s always a good idea to test your baking powder if it’s been sitting in your cupboard for a while. Expired baking powder won’t give your brownies the lift they need.

Directions

Step 1: Melt the chocolate chips

Preheat your oven to 325°F. In a microwave-safe bowl, melt the semisweet chocolate chips and the butter. Stir them until they’re smooth. Let the mixture cool for 10 minutes.

Step 2: Make the batter

In a large bowl, beat the eggs, brown sugar and vanilla until they’re blended. Beat in the melted chocolate mixture. In a separate bowl, combine the flour, baking powder and salt, then gradually add the dry ingredients to the batter and beat it until it’s well mixed. Stir in the marshmallows and dark chocolate chips.

Step 3: Add the toppings

Spread the batter into a parchment-lined 13×9-inch baking pan. Warm the peanut butter slightly in the microwave for 30 seconds. Spoon the peanut butter and marshmallow creme over the brownie batter.

Swirl the peanut butter and marshmallow creme with a knife.

Step 4: Bake the brownies

Bake the brownies for 25 to 30 minutes or until a toothpick inserted in the center comes out clean (do not overbake them). Cool them completely on a wire rack before slicing them.

Fluffernutter Brownies Variations

• Add crunch: Instead of creamy peanut butter, use crunchy peanut butter in the topping. You can also stir chopped peanuts into the batter.
• Try another chip flavor: Instead of dark chocolate chips, fold white chocolate, milk chocolate or peanut butter chips into the brownie batter.
• Mix in freeze-dried fruit: Add crushed, freeze-dried raspberries or strawberries to the Fluffernutter brownie batter.

How to Store Fluffernutter Brownies

Once the Fluffernutter brownies are completely cool, cover the pan tightly or transfer the sliced brownies to an airtight food storage container. Store the brownies at room temperature.

How long do Fluffernutter brownies last?

Fluffernutter brownies will last for three to four days at room temperature. Longer than this, and the marshmallow creme topping may begin to get chewy. Be sure to keep them tightly covered to keep the brownies moist. Fluffernutter brownies can be refrigerated for up to two weeks, or frozen for up to three months.

Fluffernutter Brownies Tips

What’s the best way to tell when brownies have finished baking?

Overbaking is a classic brownie-making mistake because it can be hard to tell when to pull them out of the oven. For moist brownies like these, they’re finished baking when a toothpick inserted in the center shows a few streaks of batter (but not fully coated) and a few crumbs. The brownies will also start pulling away from the pan around the sides. It’s a good idea to use an oven thermometer to make sure your oven’s baking temperature is accurate—for these brownies and all your baking.