Hot Cocoa Cupcakes with Marshmallow Fluff Filling

Rich chocolate cupcakes made with real hot cocoa mix, filled with marshmallow fluff filling, and topped with chocolate marshmallow buttercream

The Perfect Winter Cupcake!

If you love hot cocoa on a cold day, these cupcakes are going to steal your heart. I wanted a cupcake that truly tasted like hot cocoa—not just chocolate cake with marshmallows tossed on top.

By adding real hot cocoa mix to a doctored cake mix, filling the centers with marshmallow fluff frosting, and topping them with a chocolate marshmallow buttercream, these cupcakes deliver that cozy, comforting flavor in dessert form.

And, hey. . .isn't that what we're all looking for? Cupcakes are supposed to be comforting, as well as delicious!

Best of all, these cupcakes are simple to make, kid-friendly, and perfect for winter parties, Christmas baking, or anytime you want a little cocoa-inspired joy. They're especially perfect for the holiday season.

Why You’ll Love These Hot Cocoa Cupcakes

• Made with hot cocoa mix for authentic flavor. (It doesn't take much, I promise!)
• Soft, moist crumb using a doctored cake mix. (We're known for our doctored cake mixes here at Out of the Box Baking!)
• Hidden marshmallow fluff frosting in the center (Before you add cocoa to that frosting, stuff the inside of the cupcakes with a surprise center!)
• Chocolate marshmallow frosting = best of both worlds (Y'all. Where has this chocolate marshmallow frosting been all of my life?)
• Perfect for winter parties, bake sales, and holiday trays. (It's kind of cool to say, "Hey, y'all. . .I brought the hot cocoa cupcakes!")

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Hot Cocoa Cupcake Ingredients

You will find a full printable recipe card at the bottom of this post, as always, but I wanted to give you a quick peek at what you'll need to make these. Because they start with a box of cake mix, the ingredients are easy!

For the Cupcakes

• 1 box chocolate cake mix
• 1 cup milk, room temperature
• 3 large eggs, room temperature
• ½ cup vegetable oil
• 2 packets Nestlé hot cocoa mix

Marshmallow Fluff Filling

• Marshmallow fluff buttercream (about 1 cup, as needed)

(Note: See the recipe below for chocolate marshmallow buttercream. Before you add the cocoa powder, pull out about a cup of the white frosting to use for the centers.)

Chocolate Marshmallow Buttercream

• 1 batch Marshmallow Fluff Frosting
  • ½ cup (1 stick) room temperature butter (salted or unsalted, your choice)
  • ½ cup Crisco
  • 1 cup powered sugar
  • 1 7-ounce container marshmallow fluff
  • 1 teaspoon vanilla extract
• ¼ cup unsweetened cocoa powder OR
• 2–3 tablespoons hot cocoa mix (see notes below)

Topping

• Tiny dehydrated white marshmallow bits
• Chocolate ganache (to drizzle)

How to Make Hot Cocoa Cupcakes

Like I said above, this one comes together so easily. And it's definitely got those hot cocoa vibes! Here's how you're going to do it:

Step 1: Prep

Preheat oven to 350°F.
Line a standard muffin tin with cupcake liners.

Step 2: Make the Batter

In a large mixing bowl, combine:

• Cake mix
• Milk
• Eggs
• Vegetable oil
• Hot cocoa mix

Beat on medium speed for about 2 minutes, until smooth and well combined.

Step 3: Bake

Fill cupcake liners about ⅔ full.
Bake for 18–22 minutes, or until a toothpick inserted near the edge comes out clean.

Cool cupcakes completely before filling or frosting.

Marshmallow Buttercream

While your cupcakes are baking, make the marshmallow fluff frosting:

• Cream butter and shortening.
• Add powdered sugar and vanilla.
• Gently work in the marshmallow fluff.
• (Don't add the cocoa just yet.)

How to Fill the Cupcakes with Marshmallow Fluff Frosting

Once cupcakes are cool:

1. Use a cupcake corer, small knife, or spoon to remove a small section from the center of each cupcake.
2. Make the Chocolate Marshmallow Buttercream (instructions below) BUT don't add the cocoa powder just yet. Pull aside a cup of the white marshmallow fluff frosting and put it into a piping bag.
3. Pipe a tablespoon or so of the fluff frosting into the hold.
4. Replace a bit of the removed cake on top (optional—it helps keep the filling hidden).

Now choose one option for the remaining frosting:

Option 1: Cocoa Powder (More Chocolate-Forward)

• Beat in ¼ cup unsweetened cocoa powder
• Add 1–2 tablespoons milk if needed to loosen texture

Option 2: Hot Cocoa Mix (Sweeter, True Cocoa Flavor)

• Beat in 2–3 tablespoons hot cocoa mix
• Taste and adjust—hot cocoa mix adds sweetness as well as chocolate flavor

Tip: If you want the frosting to taste just like hot cocoa, the cocoa mix is the winner. If you want a deeper chocolate frosting, go with cocoa powder. I actually used a combination of both in mine.

Finish & Decorate

Frost cupcakes generously using a piping bag or offset spatula.

Sprinkle tops with tiny dehydrated marshmallow bits for that classic hot cocoa look. A drizzle of ganache is always a good idea, as well.

Variations & Tips

I love to change things up a bit. Here are a few suggestions:

• Add a mini chocolate drizzle over the frosting for extra indulgence
• Use peppermint marshmallow bits for a holiday twist
• These cupcakes freeze well unfrosted for up to 2 months
• Store frosted cupcakes in an airtight container at room temperature for 1–2 days or refrigerated for up to 4 days

Other Cupcake Ideas from Out of the Box Baking

If you love cupcakes, we've got you covered! Here are a few of my personal favorites:

• Apple Cider Cupcakes: These are unbelievably delicious, and perfect for the holidays!
• Pumpkin Spice Cupcakes: These have a delicious coffee frosting that takes them over the top!
• Sparkling Cranberry White Chocolate Cupcakes: Talk about a Christmas favorite! This one is almost too pretty to eat!
• Easy Espresso Cupcakes: For the coffee lover in all of us!

Final Thoughts

These Hot Cocoa Cupcakes are cozy, nostalgic, and just plain fun. The hot cocoa mix gives them a flavor people instantly recognize, while the marshmallow fluff center makes them feel extra special. They’re the kind of cupcake that makes people smile before they even take a bite—and that’s always a win.

Thanks for stopping by, friends! Before you go, why not pin some photos to your Pinterest boards? And, if you make this delicious recipe, please leave a review or comment below!

Janice Thompson is a professional baker, cake designer, and author with over 20 years of experience creating unique cakes and desserts. She’s the creator of Out of the Box Baking, where she shares her favorite doctored cake mix recipes, tutorials, and baking tips. Learn more →