Brownie Cake with Peppermint Marshmallow Frosting

A thick, fudgy, brownie cake is topped with a pillowy cloud of homemade peppermint marshmallow frosting. This will be the best dessert at your holiday table!

When thinking about holiday recipes, peppermint and chocolate immediately come to mind. This recipe features the best of these flavors. 

The brownie is super chocolatey and fudgy, and the marshmallow peppermint frosting is soft, cool, creamy and light. This holiday dessert is the perfect balance of everything you’d want during the holidays!

What is a brownie cake? 

A brownie cake is the exact same thing as regular brownies, except baked in a round form instead of a square one. For this recipe, I used a springform pan. 

I’ve been meaning to create a post for brownie cake for a while now. In my opinion, brownies are way easier to make than cakes and I love that this one is served in slices vs. bars. 

Additionally, this cake is made with just one layer, so no need to worry about stacking cakes or frosting the sides (which always stresses me out!)

How to make a Peppermint Brownie Cake

A brownie is just a brownie, but when you top it with a thick layer of peppermint frosting and crushed peppermint pieces, it instantly transforms to the perfect holiday dessert!

For the brownies, you’ll need: 

• Butter
• Granulated sugar
• Chopped chocolate or chocolate chips
• Eggs
• Vanilla
• Cocoa Powder (I prefer Dutch blend cocoa but regular unsweetened can be used)
• All purpose flour
• Salt
• Baking powder

…and, if you’re short on time you can always opt for a box brownie mix!

For the frosting…

• Egg whites
• Granulated sugar
• Light corn syrup (or agave syrup)
• Salt
• Peppermint extract

More about this amazing Frosting

This frosting is like, the most creamy, beautiful frosting ever. And, it’s made without butter!!

When experimenting with this cake, I ended up trying a few different frosting recipes. Since the brownie is so darn fudgy, I really wanted something airy and light to balance it out. Meringue would have been OK, but I find that meringue has a foamy mouth feel which I don’t really love.

This frosting is as light as meringue but creamy all the way through. Almost like Cool Whip.

It’s honestly the dreamiest frosting I’ve ever had. 

Basically, the frosting is made by beating egg whites and sugar until you achieve stiff peaks. Then with the mixer on, drizzle in hot corn syrup. 

The corn syrup cooks the egg whites and brings everything together.

This frosting has total marshmallow vibes, a perfect complement to this giant brownie. It’s a really fun way to dress up this cake and it is SO good!! 

Making the brownie cake

The brownie part of this cake is very straightforward. 

Homemade brownies are easy to make, but you can certainly always go with a box mix here. No shame! 

This brownie recipe is my favorite. It always yields a rich, ultra fudgy brownie. I like to sneak in a couple tablespoons of black cocoa powder as well to deepen the chocolate flavor. 

I recommend baking this cake in a springform pan. The sides of the brownie caramelize and it probably wouldn’t be easy to flip out of a regular round cake pan. 

Be sure to grease the bottom and sides of the pan well with shortening. 

Serving this cake

This cake is best served after it’s had time to set for a bit. If possible, make it a day in advance. By the second day, I found the brownie to be more dense and more fudgy. 

I would also wait to frost this cake until right before serving. It is very hard to store this cake because the frosting can get a little messy all over the plastic wrap. You can definitely make the frosting a few hours ahead of time and keep it aside at room temp until you’re ready to add it to the cake. 

If you’re planning to decorate with chopped peppermint pieces as I did, note that the candy will melt into the frosting after a few hours. Garnish with candy or sprinkles right before serving. 

Brownie Cake with Peppermint Marshmallow Frosting

A thick, fudgy, brownie cake is topped with a pillowy cloud of homemade peppermint marshmallow frosting. This will be the best dessert at your holiday table!

• Author: Liz at Owlbbaking.com

Ingredients

For the Brownie Cake

• 1 c unsalted butter (or two sticks, does not need to be room temp)
• 2 c granulated sugar
• ½ c semisweet chocolate chips (or your favorite chopped chocolate)
• 4 eggs
• 2 tsp vanilla extract
• ⅔ c Dutch-process cocoa powder (unsweetened cocoa powder can also be used)
• 1 c all purpose flour
• ½ tsp salt
• ½ tsp baking powder

For the Frosting

• 3 egg whites (room temp)
• ⅛ tsp salt
• ¼ c granulated sugar
• ¾ c light corn syrup (agave syrup can also be used)
• ½ tsp peppermint extract

Instructions

For the Brownie Cake

1. Preheat the oven to 350°F. Grease a 9″ springform pan with shortening.
2. In a large microwaveable bowl, heat the butter on high until fully melted.
3. Stir in sugar and chocolate chips until smooth and silky. The heat of the butter should melt everything together.
4. Allow the butter mixture to cool slightly and come back to room temp.
5. When ready, add eggs, then the vanilla extract, mix well.
6. In a separate bowl, whisk together the cocoa powder, flour, salt, and baking powder.
7. Add the dry ingredients to the wet mixture and gently fold & stir together until there are just a few small clumps in the batter. Do not over mix.
8. Pour the batter into the prepared baking pan and bake for about 40-45 minutes. The top should have large cracks and if you insert a knife into the middle, it should be just about clean.
9. Allow the cake to cool completely on a wire rack before removing the mold.

For the Frosting

1. In the bowl of a stand mixer fitted with a whisk attachment, beat the egg whites and salt until foamy.
2. With the speed on high, add the sugar in a slow and steady stream. Do not rush adding all the sugar at once as this could deflate the egg whites. Beat until stiff peaks form.
3. In a small pot, heat up the corn syrup on medium high until it begins to boil. Once boiling, remove from the heat.
4. With the mixer on high speed, drizzle in the hot corn syrup slowly until it is all added.
5. Beat the frosting for about 3-5 minutes until you reach a spreadable consistency. Add the peppermint extract last.

Equipment

Springform Pan

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Notes

Recipe by Owlbbaking.com

• For dark chocolate brownies, add 2 Tbsp black cocoa powder at step 6.
• This cake is best served after it’s had time to set for a bit. If possible, make it a day in advance. By the second day, I found the brownie to be more dense and more fudgy.
• Frosting will hold at room temp. It is best to frost the cake just before serving as storing a frosted cake can get messy since this frosting is so soft.
• If you’re planning to decorate with chopped peppermint pieces as I did, note that the candy will melt into the frosting after a few hours so only add candy right before serving.

Keywords: Brownie cake, Holiday Cake, Christmas Cake, Peppermint Frosting