Marshmallow Pecan Brownies Recipe

Pull them out just before they look done. That jiggles-in-the-middle moment—that’s when you stop. Then the marshmallows go straight on the hot pan and everything goes chaotic in the best way. The cocoa icing drips over the top while it’s still warm, pools into all the gaps, and basically glues the whole thing together. Had a box of brownie mix and half a bag of marshmallows one Tuesday. Decided to layer them instead of eating them separately. This is what happened.

Why You’ll Love These Chocolate Brownies

Takes 65 minutes total but most of it’s just waiting around. The actual work is maybe 15 minutes of stirring and watching things puff.

No bake element exists—technically. You’re baking once, then assembling. Feels like cheating but tastes like you spent actual time.

Marshmallows get puffy and shiny but stay chewy inside. Pecans stay crispy somehow, even buried in chocolate icing. Texture does something unexpected.

The cocoa icing sets just enough to hold everything together but soft enough that it gives when you bite. Not hard shell, not liquid. Just right.

Leftover brownies taste better the next day. The icing firms up more, marshmallows get slightly denser. Cold from the counter—not the fridge.

What You Need for Chocolate Brownie Recipes

One box brownie mix. Follow the package directions exactly except you pull it out early—edges pulling away from the pan, middle still visibly jiggly. That’s the moment.

Mini marshmallows. Two cups. Not the big kind. Big ones take too long to puff and you’ll burn the edges waiting.

Pecans, toasted and chopped. One cup. Raw pecans taste flat. Toasted ones are the whole point—they stay crispy inside the gooey situation. Not walnuts. Pecans have a different thing going on.

Unsalted butter, four tablespoons. This is for the cocoa icing, not the batter.

Sour cream, room temperature. Two-thirds cup. Cold sour cream seizes up when it hits hot cocoa. Room temp matters here.

Unsweetened cocoa powder. Three tablespoons. Not the sweetened kind. You’re adding sugar anyway.

Granulated sugar. Two cups. This is a lot. The icing should taste rich and almost fudgy, not like chocolate sauce.

Vanilla extract. One teaspoon. Pure, not imitation. Imitation tastes chemical against the cocoa.

How to Make Easy Chocolate Brownies

Heat the oven to 350 degrees. Mix the brownie batter straight from the box instructions but watch it the whole time. Bake until the edges start pulling away from the sides of the pan and the middle still wobbles when you shake the pan gently. Not fully set. This takes maybe 20 to 24 minutes depending on your oven. Pull it out.

While it’s still hot from the oven, scatter the mini marshmallows evenly across the top. You’ll hear them start making soft popping sounds right away. Watch them puff and go shiny and puffy. They’ll swell up pretty noticeably. This takes about five or six minutes. Stop before you see any browning starting to happen on the marshmallows because they’ll taste bitter if they brown. Once they’re puffed and shiny, pull the pan out.

Sprinkle the toasted pecans immediately over the warm marshmallows. Some of them will sink slightly into the marshmallow as it’s still warm. That’s what you want. The nuts stay crunchy even surrounded by warm gooey stuff because of that initial toast.

How to Get the Icing Perfect for Chocolate Brownie Fudge

Melt the butter in a medium saucepan over medium-high heat. Once it’s melted and starting to get hot, whisk in the cocoa powder and sour cream at the same time. Keep whisking until it’s completely smooth. This mixture will start to bubble and steam. It should look deep and thick like velvet. The second it starts boiling lightly, pull it off the heat. Cocoa can taste bitter if you let it stay on heat too long.

Add the sugar and vanilla to the hot cocoa mixture. Stir until the sugar completely dissolves. This takes a couple minutes of actual stirring. The icing will be thick and glossy and still hot.

Let it cool—this is the part where patience matters. Twelve to seventeen minutes, somewhere in there. It needs to be warm enough to stay pourable but cool enough that it won’t melt the marshmallows or collapse the pecans when it hits the top. If it’s still steaming hot, wait more. If it’s cooled completely, you can reheat it gently but just barely.

Pour it over the marshmallow and pecan layer using a spatula to spread it. It’ll pool into all the gaps and cling to the nuts and marshmallows. Some will coat everything, some will pool in low spots. All of it works.

Easy Brownie Recipe Tips and Storage

Let the whole pan sit on a cooling rack for at least 40 minutes before you even think about cutting it. The icing needs time to set and firm up slightly. The marshmallows need to stop being totally liquid inside. Cut it too early and you get a melted mess. Forty minutes is minimum. An hour is better if you can wait.

Use a sharp serrated knife for cutting. Wipe the blade clean between each cut—the icing and marshmallow will stick to it otherwise. Wiping helps the slices stay neat and not fall apart. Cut squares stay intact instead of falling into a gooey heap.

Keep them covered in an airtight container. Room temperature is fine. Don’t put them in the fridge because the marshmallows go completely hard and the icing gets waxy. They taste totally different cold. They’re meant to be soft and chewy. Room temperature keeps everything the right texture for days.

These keep for about five days before the marshmallows start going stale. Most of them will be gone before that happens anyway.

Marshmallow Pecan Brownies Recipe

By Emma

Prep:

40 min

Cook:

25 min

Total:

1h 5min

Servings:

12 servings

Ingredients

• 1 box brownie mix, follow package but pull 5% early
• 2 cups mini marshmallows
• 1 cup chopped pecans, toasted
• 4 tbsp unsalted butter
• ⅔ cup sour cream, room temp
• 3 tbsp unsweetened cocoa powder
• 2 cups granulated sugar
• 1 tsp pure vanilla extract

Method

1. 1 Heat oven to 350F. Prepare brownie batter per box but stop baking just shy of set; middle jiggles but edges pulling away. Remove pan; oven stays on.
2. 2 Scatter marshmallows evenly over hot brownies. Listen for soft pops and watch them puff. Marshmallows will swell and get shiny—not yet golden—about 4-6 minutes. Remove before browning patches appear since bitterness ensues fast.
3. 3 Sprinkle toasted pecans immediately after marshmallow puff. Let some warm stick — nuts retain toasty crunch amidst goo.
4. 4 Straight to stovetop: melt butter in medium saucepan over medium-high heat. Whisk in cocoa powder and sour cream until smooth and just boiling; looks thick, deep velvet. Remove from heat promptly to avoid bitterness and curdling.
5. 5 Add sugar and vanilla to hot cocoa mixture; stir until sugar dissolves completely. The icing needs cool down 12-17 minutes, until just warm and pourable but no longer hot enough to melt nuts or collapse marshmallows.
6. 6 Drizzle glossy icing over the pecan-marshmallow mound with a spatula. Icing pools into crevices and clings lightly to nuts—giving texture contrast when set.
7. 7 Let cool at least 40 minutes on rack to solidify icing and firm marshmallows with nuts in place. Resist cutting early or messy squares await.
8. 8 Once cooled, cut with a sharp serrated knife, wiping blade between cuts. Slices stay intact—gooey but not falling apart. Keep stored airtight; room-temp, not fridge or marshes harden.

Nutritional information

Calories

320

Protein

3g

Carbs

45g

Fat

15g

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Frequently Asked Questions About Easy Brownie Recipes

Can you make brownies without an oven? Not this version. You could skip the cocoa icing and marshmallows and just make brownies in a microwave or on a stovetop, but then you’re making a different thing. This recipe needs the oven.

What if you use a different cocoa powder? Dutch-process cocoa works but tastes less sharp. Natural unsweetened cocoa gives you more of that cocoa bite. Dutch is smoother. Either works, tastes different.

Can you substitute the sour cream? Greek yogurt works. So does regular yogurt. You might need a little less because they’re thinner. Cream cheese too, but it changes things. Haven’t tried it with anything else.

Do the pecans have to be toasted? They don’t have to be. Raw pecans are fine if that’s what you have. They just taste flatter and softer inside the marshmallow. Toasted ones stay crispy and their flavor actually shows up.

What if the icing breaks or curdles? This happens if you add cold sour cream to super hot cocoa or if you overheat the cocoa powder. If it breaks, start over. It’s quick. Let sour cream reach room temperature first. That matters.

How thick should the marshmallows puff? They’ll roughly double in size. Maybe a bit more. You’re looking for shiny and puffy, not brown. About a quarter inch taller than where they started. That’s the visual cue.