Hot Chocolate Layer Cake with Homemade Marshmallows

Sometimes, you just gotta bake a cake. At least that's how I was feeling last weekend. I had absolutely no reason to bake a gigantic cake, but I did it anyways. You know why? Because I felt like it. And that's just one of the joys of being an adult. You can bake a cake just for the hell of it.

And this was one hell of a cake. I had my eye on making it ever since I saw it in the October issue of Fine Cooking magazine. I loved the idea of a hot cocoa flavored cake with the quintessential marshmallow topping, made even more special by making the marshmallows from scratch.
I would say that this cake is a bit of a labor of love as it took up a good chunk of my Saturday to make it. But I can’t think of a better weekend project than one that results in layers of delicious hot chocolate cake, and light and fluffy homemade marshmallows. If you wanted to save some time however, each of the 3 main components of the cake can be made up to a day ahead of time and then assembled at your convenience.

It probably would have been better if I had staggered the cake making process a bit, as I became a bit of a slacker towards the end of it. Basically I was lazy about putting the cake together. You see, I’m not the best at making food look aesthetically pleasing. If it tastes good that’s usually enough for me, and I therefore tend to get a bit sloppy in the looks department.

For example, I should have cut off the tops of each of the cake layers to get rid of the crusty tops and to make them flat. I should have done a crumb coat (spreading one layer of the frosting on the outside of the cake, putting it in the fridge to set, then spreading another layer of frosting on to create a smoother coat). And I should have given the frosting more time to set up as it was still a little loose as I was putting it on. But I didn’t do any of these things, which makes me think that my dreams of one day owning my own bakery is unrealistic, as nobody likes to pay for sloppy cakes. Oh well, I’m not sure I could handle the early-morning hours of being a baker anyways.Even with less than stellar construction, this cake still looks pretty impressive. But then again, topping anything with homemade marshmallows is always sure to impress. I decided to make the marshmallows first. I had made marshmallows once before, using this recipe, and so I knew that they could be a little tricky. The only reason they’re tricky however, is because they’re just so darn sticky, and they have a tendency to get all over you and your kitchen while you’re making them.
The actual process of making the marshmallows is not difficult though. Gelatin is mixed with cool water in the bowl of a mixer, and as that hangs out, sugar, corn syrup and water are brought up to 235°F in a pot on the stove. A candy thermometer is an important tool for this, as it needs to be right around that temperature in order to work.
Once the mixture has reached the right temperature it's added to the gelatin and water in the mixer, and mixed on high until it's cooled down a bit. As you can see the marshmallow mixture will still be very soft at this point. It's gonna need some time to set up.
Which is what a pan covered in powdered sugar is for! This recipe called for covering the bottom and sides of the pan with tinfoil and then sprinkling with powdered sugar, but I had more difficulty with this method as I had a really hard time separating the marshmallows from the tinfoil. If I were to do it over again I think I would stick with the other method I had tried which involved oiling the pan and then covering it in powdered sugar.

Next up was the cake. Butter, chocolate, oil and water is melted in a pan.
Flour, sugar and cocoa powder is whisked in a bowl.
And then the two mixtures get combined together along with the eggs, buttermilk, vanilla, baking soda and salt.

Here's a quick tip: it's almost always best to have all the ingredients at room temperature when baking. This involves planning ahead however, which does not always happen in my kitchen. Eggs however, can be brought up to room temperature by simply running them under lukewarm water for a couple of minutes. Pretty cool huh?
Once your cake batter is all set, pour it into prepared 9 x 2 inch cake pans. The recipe says that it should make three layers of cake, I found that I actually had enough for four. Unfortunately, I only own two cake pans, not four, so I had to take turns baking the cakes.
After the cakes were done, I got to work making the frosting. Where are the pictures of the frosting you may ask? Well, there aren't any. Ummm, yeah. I'm not quite sure what happened there, but unfortunately they don't exist.

I can tell you though that this frosting called for a technique that I have never seen before. Once the frosting is mixed, it gets placed in a freezer for a couple of hours to set up, and then it gets whipped again until it's light and fluffy. As I said before however, I was a little bit sloppy and did not give it enough time to set up. As a result, my frosting was looser than it probably should have been.

Finally it came time to assemble the cake. Here's a good tip for assembling a frosted cake. Place strips of waxed paper on whatever cake stand or plate you plan on using, and then frost the cake on top of them. When you are done, simply pull the strips out from under the cake and your serving dish will be completely clean.
Even though the marshmallows were a bit trying at times, I absolutely loved the way they looked on top of the cake.
And if you've never tried a homemade marshmallow before, it's definitely worth the effort. Plus, this recipe made plenty, so there will be some to snack on once the cake is long gone.

So if you find yourself one day thinking that you just gotta bake a cake, here's one to try.

Hot Chocolate Layer Cake with Homemade Marshmallows
From Fine Cooking, October 2009

For the cake
6 oz. (3/4 cup) unsalted butter; more for the pans
13-1/2 oz. (3 cups) unbleached all-purpose flour; more for the pans
3/4 cup canola oil
4-1/2 oz. bittersweet chocolate, finely chopped
3 cups granulated sugar
2-1/4 oz. (3/4 cup) natural unsweetened cocoa powder
3 large eggs, at room temperature
3/4 cup buttermilk, at room temperature
2 Tbs. pure vanilla extract
2-1/2 tsp. baking soda
1/2 tsp. kosher salt

For the frosting
2-1/2 cups heavy cream
3 oz. (6 Tbs.) unsalted butter
1 vanilla bean, split lengthwise and seeds scraped out
6 oz. bittersweet chocolate, finely chopped
2 cups granulated sugar
6 oz. (2 cups) natural unsweetened cocoa powder; more for decorating
1/2 cup Lyle’s Golden Syrup
1/4 tsp. kosher salt

For the marshmallows
Three 1/4-oz. envelopes unflavored powdered gelatin
2 cups granulated sugar
1 cup light corn syrup
1/4 tsp. kosher salt
1 tsp. pure vanilla extract
1 cup plus 2 Tbs. confectioners’ sugar; more as needed

Make the cake
Position racks in the bottom and top thirds of the oven and heat the oven to 350°F. Butter three 9x2-inch round cake pans and line each with a parchment round. Butter the parchment, then dust with flour and knock out the excess.
In a 3-quart saucepan, combine the butter, oil, chopped chocolate, and 1 cup water. Heat over medium heat until melted.
In a large bowl, whisk the flour, sugar, and cocoa powder. Pour the hot chocolate mixture into the sugar mixture and whisk until combined.
Whisk in the eggs, one at a time, then whisk in the buttermilk, vanilla, baking soda, and salt. Divide the batter evenly among the prepared pans.
Set two pans on the top rack and the third on the lower rack. Stagger the pans on the oven racks so that no pan is directly over another. Bake, swapping and rotating the pans’ positions after 20 minutes, until a toothpick inserted in the center of each cake comes out clean, 35 to 40 minutes. Cool on racks for 10 minutes. Invert the cakes onto the racks, remove the parchment, and cool completely.

Make the frosting
In a 4-quart saucepan over low heat, combine the cream, butter, and vanilla bean and seeds and stir until the butter is melted. Remove the vanilla bean and whisk in the chopped chocolate until melted. Whisk in the sugar, cocoa powder, syrup, and salt until smooth—be sure the cocoa powder dissolves completely. Pour into a 9x13-inch pan and freeze until firm, about 2 hours, or refrigerate overnight.

Make the marshmallows
Pour 3/4 cup cold water into the bowl of a stand mixer. Sprinkle the gelatin over the water. Attach the bowl to the mixer and fit it with the whisk attachment.
Clip a candy thermometer to a 3-quart saucepan; don’t let the tip of the thermometer touch the bottom of the pan. In the saucepan, boil the sugar, corn syrup, salt, and 3/4 cup water over medium heat without stirring until it reaches 234°F to 235°F, about 10 minutes. With the mixer on low speed, pour the hot sugar mixture into the gelatin in a slow, thin stream.
Add the vanilla, carefully increase the speed to high, and beat until the mixture has thickened and cooled, about 5 minutes (the bottom of the bowl should be just warm to the touch). Line a 9x13-inch pan with foil, leaving an overhang on 2 sides. Sift 1 Tbs. of the confectioners’ sugar into the bottom of the pan, then pour the marshmallow mixture into the pan and sift another 1 Tbs. confectioners’ sugar on top. Let sit at room temperature until set, at least 2 hours.

Assemble the cake
Remove the frosting from the freezer or refrigerator. Transfer to the bowl of a stand mixer fitted with the paddle attachment and beat on medium speed for 2 minutes to soften. Change to a whisk attachment and beat at medium-high speed until light and fluffy, about 3 minutes.
Put a cake layer on a flat serving platter or a cake stand lined with strips of waxed paper to keep it clean while icing. Top the layer with 1-1/2 cups of the frosting, spreading it evenly with an offset spatula to the cake’s edge. Repeat with another cake layer and 1-1/2 cups frosting. Top with the last cake layer.

Put 1-1/2 cups of the frosting in a small bowl. With an offset spatula, spread this frosting in a thin layer over the top and sides of the cake. Refrigerate the cake until the frosting firms enough to seal in the crumbs, 20 to 30 minutes.

Spread the remaining frosting in a smooth layer over the top and sides of the cake. If necessary, you can rewhip the remaining frosting to loosen and lighten it. Remove the waxed paper strips.
Use the foil overhang to lift the marshmallow from the pan. Using a knife that has been dipped in cold water, cut along the edge of the marshmallow to release it from the foil. Transfer to a cutting board and remove the foil. Put the remaining 1 cup confectioners’ sugar in a medium bowl. Cut the marshmallow into cubes of different sizes, from 1/4 to 3/4 inch (you will need to continue to dip the knife in cold water as you cut the marshmallows). The marshmallows will be very sticky—dip the cut edges in the confectioners’ sugar to make them easier to handle. As you work, toss a few cubes at a time in the sugar to coat, then shake in a strainer to remove the excess. Mound the marshmallows on top of the cake (you’ll need only a third to half of them). Sift some cocoa powder over the marshmallows.

Make Ahead Tips
You can bake, cool, wrap, and store the cake layers at room temperature for up to 1 day or freeze for up to 1 month. You can refrigerate the frosting for up to 3 days. The assembled cake can be refrigerated for up to 4 hours (return to room temperature before serving). Wrapped well, leftover marshmallows keep at room temperature for up to 1 month.