Hot Chocolate Cake with Marshmallow Frosting

Name: Hot Chocolate cake
Prep time: 60 min
Cook time: 25 min
Total time: 325 min
Ingredients: 2 1/4 cup (270g) all-purpose flour (spooned and leveled); 3/4 cup (60g) unsweetened cocoa powder (spooned and leveled (I use dutch-processed)); 1 Tbsp baking powder; 1 tsp fine sea salt; 1/2 cup (113g) unsalted butter (room temperature); 2 cups (400g) granulated sugar; 1/2 cup (120mL) vegetable oil; 4 large eggs (room temperature); 2 tsp vanilla extract; 1 cup (225g) sour cream (room temperature); 1 cup (237mL) milk (room temperature); 1/2 cup (113g) salted butter (cold or room temperature); 1/2 cup (100g) granulated sugar; 1/2 cup (120mL) milk; 1/4 cup (20g) dutch-process cocoa powder (spooned and leveled); 2 cup (454g) unsalted butter (room temperature); 7 cups (840g) powdered sugar (spooned and leveled); 1 Tbsp vanilla bean paste (OR vanilla extract); tiny pinch fine salt; 30 large marshmallows (OR 2 cups (6oz) marshmallow fluff)

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This Hot Chocolate Cake is made with four layers of chocolate cake drenched in chocolate fudge sauce (aka like a thickened hot chocolate) and frosted with a marshmallow frosting. Top it off with more marshmallows and a drizzle of chocolate fudge sauce.

hot chocolate cake topped with marshmallows and chocolate fudge sauce with a few slices removed

Hot chocolate is one of those things for me like s’mores. I don’t really like hot chocolate and I don’t really like actual s’mores but I LOVE anything hot chocolate flavored or s’mores flavored.

Why you’ll love this hot chocolate cake

The cake has a more ‘milk chocolate’ flavor than traditional chocolate cakes.
There’s a chocolate fudge sauce that tastes just like hot chocolate but has a thicker consistency – this fudge gets into every nook and cranny of the cake!
The recipe is forgiving – works well with dairy free butter and milk, and gluten-free flour.
It’s rich, sweet and super indulgent, just like hot cocoa should be.

For more hot chocolate recipes make sure to check out my hot chocolate cupcakes and hot chocolate brownies.

Some other fabulous cakes to try this holiday are my chocolate ganache cake (for all the dark chocolate lovers), 6 layer Gingerbread Cake, the BEST Tiramisu Cake, Ferrero Rocher Cake, Brownie Cake, White Chocolate Cranberry Cake and Creme Brulee Cake!

slice of hot chocolate cake on a plate with a fork

Ingredients

Flour: I use all purpose flour in most of my recipes and I HIGHLY recommend using a digital scale, as flour (and cocoa) is so often over measured.
Cocoa Powder: make sure to use unsweetened cocoa powder. I use dutch-processed but natural cocoa powder also works. The color and flavor will be slightly less intense with natural cocoa powder.
Baking Powder: I used just baking powder here. If you only have baking soda, you can just use 1 tsp of that instead.
Sugar: I used granulated sugar in the cake but brown sugar would also work well in this cake. I don’t recommend cutting any out as it affects the texture and the flavor.
- For the frosting I used powdered sugar. You could reduce the amount used in the frosting but it may make the frosting too soft so make sure to refrigerate it a little before frosting.
Butter: I like to use salted butter in my cakes but you can also use unsalted butter. Dairy free butter also works well.
- I recommend unsalted butter for the frosting though.
Oil: I usually use a neutral oil like sunflower, vegetable or canola oil but olive oil also works well here as it pairs well with chocolate and is hardly noticeable.
Eggs: make sure to use room temperature, large eggs.
- Place them in hot water for a few minutes if they’re cold.
Sour cream: I love the combination of sour cream and milk for cakes. The sour cream can be replaced with plain yogurt or greek yogurt. Make sure it is unsweetened though.
Milk: I use whole milk or 2% milk but any milk works fine, even dairy free milk.
Marshmallows: I used marshmallows here and microwaved them until they were puffed and melty inside but marshmallow fluff also works fine.
- If you want, you could toast the marshmallows or the fluff like I did in the cupcakes before adding to the frosting as well. I didn’t want that because I wanted a nostalgic flavor and growing up we just had plain marshmallows in our hot chocolate lol.

Step-by-Step Instructions

Chocolate Cake

Step 1: Make the cake first. Start by creaming the butter with the sugar for 1-2 minutes. Then add the oil and beat at full speed until it’s pale and fluffy.

Step 2: Add the eggs one at a time. Make sure each egg is fully incorporated before adding the next egg. Then add the vanilla and sour cream, mixing just until they’re combined.

Step 3: Add half of the dry ingredients, followed by the milk and the other half of the dry ingredients. Make sure to scrape the bottom and sides of the bowl well so it’s evenly mixed.

Step 4: Distribute the batter evenly. You should get about 11 ounces in four 8 inch cake pans.

Step 5: Bake for about 20-25 minutes. When the cake is done baking, it will release itself from the edge of the pan and spring back when you press on the center. Flip the cakes over onto a cooling rack or a tea towel right away. Allow them to cool completely to room temperature.

bowl of butter, sugar and oil creamed — sugar, butter and oil beaten

bowl of batter after the eggs and sour cream are added — sugar, butter and oil beaten

Chocolate Fudge Sauce

Step 1: Place the butter in the saucepan and heat it just until it’s melted.

Step 2: Add the sugar and cocoa powder, mixing until it’s smooth and then add the milk, whisking until it’s smooth.

Step 3: Bring it to boil and then turn the heat off and whisk for a few seconds.

Step 4: Pour the hot fudge into a heat resistant bowl and allow to cool to room temperature.

Marshmallow Frosting

Step 1: Beat the room temperature butter until it’s pale and fluffy, just a couple of minutes.

Step 2: Add the powdered sugar and salt, and beat until it’s smooth. Then add the vanilla extract, beating just until it’s combined.

Step 3: Place the marshmallows in a large bowl and microwave for 30-45 seconds. They should get puffed up, which means they’re melty inside. Remove them from the microwave and let them cool for just up to a minute or so.

marshmallows in a plate — 15 large marshmallows before microwaving (I did two of these plates)

marshmallows melted — 15 large marshmallows before microwaving (I did two of these plates)

Step 4: While they’re still a little warm and melty, add the marshmallows to the frosting. This will make your frosting warmer and softer so once it’s completely mixed. Place the bowl in the fridge for about 30 minutes, mixing halfway through. Depending on how warm it got and how warm it is in your house, it may take 60 minutes to firm up.

marshmallow frosting in a mixer bowl — finished marshmallow frosting

Assemble

Step 1: Once everything has cooled and the frosting is chilled, poke some holes into the top half of your cake and spread a thin layer of the chocolate fudge sauce. Keep spreading it around, trying to make it go into the holes.

chocolate cake with holes poked on the top

fudge sauce spread on chocolate cake — chocolate cake with holes poked on the top

Step 2: Spread a layer of frosting on top of the fudge sauce and then pipe a border of frosting around the edge of the cake. I do this border fairly short (in height) because we’re just doing a thin layer of fudge sauce in the center but make sure the border is secure and there are no disruptions or the fudge sauce will run out.

Step 3: Fill the border in with the chocolate fudge sauce and freeze the cake for 15 minutes or so. Repeat until the last layer of cake. I do the holes with the fudge sauce on top too and then freeze it for 30-60 minutes to make sure it’s sturdy before frosting the outside.

frosting with border piped around the edge

assembled hot chocolate cake — frosting with border piped around the edge

Step 4: Use the rest of the frosting to lightly frost the cake (if you want to frost the cake fully, you’ll need at least another half batch of frosting and if you want to decorate the cake, you’ll need another full batch but I recommend skipping the marshmallows for frosting and decorating).

Step 5: Place a bunch of marshmallows on top of the cake and then drizzle with the chocolate fudge sauce.

cake topped with marshmallows and chocolate sauce

Expert tips on getting perfect hot chocolate cake

Don’t swap ingredients unless I mentioned them in the ingredient section above.
Don’t reduce the sugar. I know a lot of people do that for some recipes but not don’t do it for the cake part. The frosting is very sweet so feel free to use less of it between the layers or reduce the powdered sugar a little. This will make the consistency of the frosting softer though so you’ll likely need to refrigerate for a little longer than I did, before frosting the cake.
Weigh your ingredients with a digital scale.
Weigh the batter for each cake tin with a digital scale. I just place each cake tin on the scale and measure out about 11 ounces of batter into each.

Can I use a different type of frosting?

I included this section for people who are picky about their frosting like I am lol. I used American Buttercream because when I tested this with frosting that was less sweet, Ermine Frosting, the marshmallow flavor doesn’t come through… like almost at all.

If you don’t care and still prefer that, you can double this Ermine Frosting Recipe. What I did was pour the cooked mixture over 20 large marshmallows, cover it for 1-2 minutes to warm them up and then mix them into the whole mixture. Allow it to cool completely, I put it in the fridge to firm it up a little and then mix it with the butter. Again, I thought it still mostly just tasted like plain buttercream lol.

Even with just 20 marshmallows I feel like this frosting was not quite as stable as the American buttercream with 30 marshmallows. That’s probably why I couldn’t get the flavor to come through.

The same thing would happen if you used any European based butter like Swiss Meringue, Italian or French, etc. Those are much more stable than Ermine but they are incredibly difficult to flavor so I don’t think the marshmallow would ever come through. You could try a marshmallow extract though…

If you want to decorate this cake fancy (like pipe work, etc.) I would make a double batch of Swiss meringue buttercream or plain American buttercream to decorate (recipe in the recipe card but without the marshmallows – you can play around with the amount of sugar for flavor/consistency as well).

Frequently Asked Questions

Can I make this ahead of time?

This cake holds on to moisture really well because it’s drenched in fudge sauce so you can make it a few days in advance before serving. Store it covered in the fridge after it’s completely frosted.

What if I don’t have four pans?

You can bake all of the batter in two cake pans and cut them in half or bake them in three cake pans and just do three 18 ounce layers. Or you can do just two layers at a time if you have only two pans and then bake the other half.
If you bake all of the batter in two pans, there’s a higher chance the cakes will dome so when you go to cut them in half, you may have to trim them first and then you’ll end up with slightly thinner layers.

How do I know when it’s done baking?

Just like all the rest of my cakes, I test if it’s done baking by pressing gently on the tallest part of the cake. The cake will spring back if it’s done baking. If it stays indented, give it a few minutes in the oven, before testing again.

Can I use this as a hot chocolate cupcake recipe?

I haven’t tested this cake as cupcakes but I do have a hot chocolate cupcake recipe if you want 🙂

Do I have to make the fudge sauce?

Personally, this was my absolute favorite part of the cake. If I could drink it, I would… lol
You can skip it but you’ll lose some of the fabulousness, and it really is sooo easy!

How to store this hot chocolate cake

I usually just cover the cake with a cake dome or cover it with plastic wrap and store it in the refrigerator for about 2-3 days but if it’s any longer, I recommend freezing the cake.

To freeze the cake, refrigerate it until it’s firm, then wrap it in plastic wrap, twice and then wrap it in foil and freeze.

To freeze slices, place them in an airtight container OR wrap them in plastic wrap and then place the container in a freezer bag, squeezing out all the excess air. Bring them back to room temperature by thawing at room temperature for a few hours before serving.

Thanks so much for reading today’s post, if you have any questions just comment down below.

If you make this hot chocolate cake, I’d love it if you left me a star rating or a review.

As always, have a blessed day and happy baking!

Love, B

Hot Chocolate cake

5 from 10 votes

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Prep Time 1

Cook Time 25

Total Time 5 25

Course Cakes

Cuisine American

Servings slices

Calories 871 kcal

Equipment

1 stand mixer or hand mixer
1 Rubber Spatula
1 offset spatula
1 Round Piping Tip
1 piping bag
1 small bowl
2 8 inch cake pans
1 digital scale