A marshmallow brownie, with its rich, dark chocolate base and gooey marshmallow topping, is a decadent treat sure to be the show stopper of any gathering. Combining the deep, intense flavor of cocoa with the sweet, melt-in-your-mouth texture of marshmallows, these brownies offer a delightful contrast that’s both indulgent and irresistibly delicious (emphasis on “irresistibly”!).

Marshmallow brownies are more than just a sweet treat; they’re a sensory experience. The combination of the dense, chocolatey brownie with the soft, fluffy marshmallow creates a dessert that’s as visually appealing as it is tasty.

Marshmallow brownies being scooped from the pan onto a platter

What is in a marshmallow brownie?

Unsalted Butter

It is always important to use unsalted butter when baking. If you use salted butter, you have no way of knowing how much salt you are adding to your dough or batter and it will result in an overly salted treat.

Butter adds fats to your dough or batter which helps with moistness, flavor and texture. Butter melts at body temperature, which creates a ‘melt in your mouth’ sensation.

When baking with butter the temperature is important. If the butter is too warm your treat will melt down too fast and overspread in the oven, leaving you with a greasy, flat mess. If your butter is too cold it will have the opposite problem and not melt down enough, leaving your treat too thick.

Granulated Sugar

Adds sweetness, provides a caramelized flavor and crisp texture. Sugar assists with rising when creamed with butter. It helps add moisture to your treat and helps it evenly spread as it melts into a liquid in the heat of the oven. Sugar also helps with naturally preserving your baked treat.


Adds both a protein (egg whites) and fat (egg yolks). The egg whites help with rising because, when foamed, little air pockets get trapped inside the egg white mixture. The water content in egg whites encourages steam while baking, which helps with gluten formation, resulting in nice and thick treats. Egg yolks have emulsifying properties that bring batters and doughs together and help them from collapsing. Unless otherwise specified, always use large eggs.

Vanilla Extract

When using pure vanilla extract, as opposed to imitation flavoring, it will add the deep rich flavor that everybody wants in a treat.

Cocoa Powder

Provides a rich, sweet chocolate flavor. Creates a dark brown color in your treat. Absorbs water in your batter or dough at the same rate as flour. That means, if you add too much, you could end up with a dried, crumbly finished product.

Mini marshmallows

Adds a sweet and gooey layer to your brownie.

Powdered sugar

Is just finely ground granulated sugar. It dissolves easily, ensuring a smooth texture without grittiness. It also stabilizes and thickens the frosting, thanks to its small amount of cornstarch.

Up close on marshmallow brownies on a tray

How do you keep a marshmallow brownie moist?

The key is not to over bake the brownie base. Remove it from the oven when it is still slightly underdone for a moist, gooey center. The best way to know that it is ready to come out of the oven is to watch for visual cues. As soon as the top of the brownies no longer look shiny, but dull, they are done. If you still aren’t sure, stick a fork right in the middle of the brownie, if a few moist crumbs come out on the fork, it is done.

Can you use different types of marshmallows?

Absolutely! While mini marshmallows are ideal for even melting, you can use larger marshmallows, cut into smaller pieces, or even try using flavored marshmallows for a twist.

How do you store the marshmallow brownie?

Store them in an airtight container at room temperature to keep them moist. They typically last for 5-7 days. If you want them to last longer, wrap in plastic wrap and then tinfoil and store in the freezer for up to a month. Just make sure to remove from the freezer and allow to completely thaw on the counter before eating.

Are there variations to the basic marshmallow brownie recipe?

Yes, there are many creative variations. You can add nuts, chocolate chips, or a swirl of peanut butter to the batter. For the topping, consider a sprinkle of sea salt or a drizzle of caramel.

Marshmallow brownies on a tray with a spatula next to them and marshmallows on the counter

Recommended Equipment

  • Standing mixer – to properly cream the butter and sugar
  • Light metal 9×13 pan – this will bake the most evenly
  • Parchment paper – to help with baking evenly & so that your brownies don’t stick to your pan

Recipes You May Love

Marshmallow Brownie

Author: Madison Reid
Prep Time: 15 minutes
Cook Time: 30 minutes
Servings: 24
These yummy, rich, dark chocolate brownies are so gooey and delicious! The hit of every gathering.



  • 1 cup unsalted butter
  • 1 cup granulated sugar
  • 4 eggs
  • 2 tsp vanilla extract
  • 3/4 cup cocoa powder
  • 2 cups mini marshmallow


  • 1/4 cup unsalted butter
  • 1/3 cup cocoa powder
  • 1 tsp vanilla extract
  • 2 cups powdered sugar


  • Preheat oven to 350 degrees
  • In a standing mixer combine butter & sugar. Beat until lighter in color and fluffy in texture (about 2 minutes)
  • Stir in eggs& vanilla extract
  • Add cocoa powder & flour, stir until combined
  • Pour batter into 9×13 greased pan
  • Bake for 27 minutes
  • Pour marshmallows on top and bake for additional 3 minutes
  • Whisk all the frosting ingredients together in a bowl with a whisk. Pour over the top of your brownies and let completely cool.


Calories: 190kcal Carbohydrates: 24g Protein: 2g Fat: 11g Saturated Fat: 7g Polyunsaturated Fat: 1g Monounsaturated Fat: 3g Trans Fat: 0.4g Cholesterol: 53mg Sodium: 16mg Potassium: 73mg Fiber: 1g Sugar: 21g Vitamin A: 335IU Calcium: 12mg Iron: 1mg

Have you tried this recipe?

I’d love to see it! Follow @_mrs.madi_ on Instagram and tag your photos with #mrsmadi.