Triple Chocolate Mousse Cake

July 22nd, 2011  |  89 Comments

A few months ago, reader Mika sent me an email asking if I could recreate a dessert that knocked her socks off at a restaurant in her home town. She wanted to be able to make it whenever the craving hit. And let’s face it, when it comes to chocolate, that could be any time of day or night. It was a Triple Chocolate Mousse Cake and she included a photo, so I could get a visual reference. Looked good to me. I was in.

But I kept peering at that photo. Did my eyes deceive me? Where, oh where was the third part of the “Triple” in the name? If I let my pastry imagination run amuck, Triple Chocolate Mousse would mean there would be three kinds of mousses — one layer each of white, milk, and dark chocolate.

I consulted the Great Sultan: Google.

Turns out, the “triple” refers to the number of layers all totaled, not the number of mousse-only layers, meaning the cake part was counted as a third. I reexamined the photo. Perhaps I needed my glasses, but the cake part was hard to see.

Ah, yes, there it was, acting as a meager bed, barely offering any reason-for-being. It felt a little sad, like sleeping on a thin mattress. In my mind, if it was to be counted as part of the “Triple”, it better step up and play a supporting role.

I decided to make the cake layer more substantial by spreading the batter a little thick before baking. This way, the dessert would offer a little cakey contrast to some of the bites. As for the mousse, any type of chocolate would work, whether it be dark, milk or white, but visually, white chocolate mousse is a perfect contrast to dark chocolate for a tuxedo-like effect. I went with those. Feel free to use whatever chocolate combos you like. If you want to do less work, you can stick with just one mousse and double the recipe, though the color contrast will be lost.

Or alternately, go bonkers. Rename the lot “Four-Chocolate Mousse Cake”, and make all three mousses.

For a little party on the tastebuds, I thought a little crunch would be of benefit. I usually can’t rest without adding a garnish and opted for a simple enhancement of chocolate-covered cereal. It ended up looking like some post-apocalyptic underwater terrain. Love it.

We also have sauce. Most desserts benefit from some kind of sauce, and now that I mention it, you may start noticing that just about all restaurant desserts do have some. Not only does it add more visual interest to a plate, all the forkfulls catch a little and help tie all the components together. It makes for a more finished presentation. And if there are kitchen mishaps, resulting in a too-dry dessert, sauce helps mask the error. Sauce is the ketchup of the dessert world.

I had some fun playing with the molds. I tried some long, skinny molds, if only for the irony of making a calorie-laden cake look like a super model. Then I had some short, wider molds to make mini cakes for 2 (or in my case, for 1). This would also work perfectly well as a large cake, set up in a ring like this.

The cake layer and the chocolate glaze get around. I’ve used the cake here, and the sauce here, and they’re two of the most versatile recipes in my repertoire. They can be dressed up in so many different ways.

This happens to be an eggless mousse, so the chocolate flavor shines through. Since the mix is a little on the loose side, I threw in some gelatin to help hold its structured shape. Keep in mind that any dessert made with gelatin gets more rubbery for each day it sits in the fridge (thanks to evaporating moisture and thus, a hardier concentration of gelatin left behind), so it’s best to consume it the day you defrost it.

Let’s hope this one stands tall and proud and does the original version justice. Only Mika can say for sure.

Individual Triple Chocolate Mousse Cakes

This recipe makes enough mousse for about eight 2″-diameter cakes, give or take, depending on the size of your molds. Make sure you have enough freezer space available to accommodate a sheet pan with ring molds.

The whole recipe must be made at least 6 hours before you plan to serve because the mousse needs a chance to set up, but if you like, you can make each step of this recipe on different days to break up the labor, and just keep it in the freezer until serving day.

There will be plenty of cake and chocolate sauce left, which can both be wrapped well and frozen, or enjoyed as a cake sundae by cutting the cake into squares, topping with a scoop of ice cream, and drizzling with chocolate sauce.

For the chocolate cake layer:
1 stick (112 g) unsalted butter
1 1/3 cups (257 g) sugar 
1/2 cup + 2 tablespoons (56 g) cocoa powder
2 large eggs
2 oz (56 g) dark chocolate, melted
1 3/4 cups (210 g) all-purpose flour
1 teaspoon (4 g) baking powder
3/4 teaspoon (3 g) baking soda
1/4 teaspoon (1 g) salt
1/2 cup (118 ml) water
1/2 cup (118 ml) milk

For the dark chocolate mousse:
1 teaspoon (3 grams) powdered gelatin 
2 tablespoons water
1/2 cup (105 g) whole milk
6 oz (175 g) good quality dark chocolate (or use milk chocolate if you prefer), finely chopped
1 1/4 cup (280 g) heavy cream

For the white chocolate mousse:
1/2 cup (105 g) whole milk
6 oz (175 g) good quality white chocolate
1 teaspoon (3 grams) powdered gelatin 
2 tablespoons water
3/4 cup (180 g) heavy cream

For the chocolate glaze and sauce:
4 oz (112g) dark chocolate, finely chopped
1/2 cup (80g) heavy cream 
3 tablespoons light corn syrup
1 tablespoon vegetable oil
1/2 teaspoon vanilla extract

For the chocolate crunch:
1 cup Rice Crispies cereal, or similar rice cereal
2 oz (56 g) dark chocolate

First, the chocolate cake base.

Gettin’ ready. You can see how sweaty my eggs are in the photo. All cold ingredients should be at room temperature for better incorporation. Preheat oven to 325 degrees F.

 

Melt the chocolate. I like to chop it up fine like in the “ingredients” photo above, and melt it in the microwave in 30-second intervals. Chocolate burns easily, so stir between every zap. Mine took about 60-90 seconds to melt. Set it aside for the moment.

 

Using a tabletop or handheld electric mixer, beat the butter, sugar, and cocoa powder together on medium high speed…

 

…until smooth, creamy and fluffy, about 3 minutes. Hard to see with the cocoa in the bowl, but this is what it looks like 3 minutes later.

 

Add the eggs, one at a time, until each one disappears into the mix. Be sure to scrape down the sides and bottom of the bowl. Looks like a rising sun, no?

 

Getting liquidy here. Scrape. The dry, gritty stuff wants to collect at the bottom. Don’t let it win.

 

Pour in the melted chocolate. Hopefully, by now your chocolate came down in temperature a little. It should feel like a warm bath. If it’s too hot, it might melt the butter, and that’s no good. If it’s too cold, it might re-solidify into little bits when it hits the cold bowl. So, warm. We want it warm.

 

So far so good. Chocolate added.

 

In a medium bowl, stir together the dry ingredients, which include flour, baking powder, baking soda and salt. Stir ’em up good.

 

Combine the milk and the water and microwave until hot, about 45 seconds. Like a “too hot” bath.

 

Drop the dry ingredients into the mixing bowl…

 

…and mix on low speed…

 

…until MOSTLY combined, and then, with the machine still running, pour in the hot water/milk mixture.

 

Be sure to scrape the bottom of the bowl again. The dry ingredients tend to hide there. Here’s the finished batter. It should be smooth and lump-free.

 

Pour it into a 18″ x 13″ sheet pan that’s been first sprayed with nonstick cooking spray and lined with parchment. (You can use any sized sheet pan with high sides — just pour in enough batter to come about halfway up the sides. If you have leftover batter, you can pour it into greased muffin tins, and bake mini cakes as well.)

 

Spread that sucker out.

 

Bake in your preheated oven for about 18 minutes. Even though I specify a time amount, everyone’s ovens have a personality of their own, so it’s better to just pay attention to what the cake looks like. Here, the top doesn’t look wet anymore…

 

…and it springs back when I do a gentle press. Let it cool to room temperature. (Cake layer can be made a day ahead, if you’d like to break up the labor of this recipe. Wrap the whole thing, sheet pan and all, with plastic very well, and refrigerate.)

 

Cut a cake circle with each ring mold, regardless of which size you’ve decided to use.

 

Here they are on a parchment lined sheet pan, eagerly awaiting mousse. Any sized sheet pan will do, so long as all your molds will fit on it, and the pan fits in your freezer.

 

Now, let’s make some dark chocolate mousse:

Make sure your dark chocolate is finely chopped and waiting in a large bowl. Resist the urge to eat the shards.

 

First we’ll rehydrate the gelatin (otherwise known as “bloom” the gelatin.) Sprinkle it evenly over a small bowl with the water.

 

In 5 minutes, it’ll have slurped up the liquid and will look, well, gelatinous.

 

Next heat up the milk to a simmer in a small sauce pan. Stay close so it doesn’t boil all over.

 

Turn OFF the heat (This is important. When subjected to high heat, gelatin deteriorates and turns grainy) and then scrape the gelatin blob into the hot milk. Swirl the pan around until it’s completely dissolved. It’ll look like there’s nothing more than milk.

 

Pour this milk/gelatin concoction over the finely chopped chocolate…

 

…and let it rest for 2 minutes. The heat from the milk will melt down the chocolate.

 

Whisk it up into a smooth pool of goodness. Set it aside and let it cool to lukewarm. Don’t let it reach room temperature or the gelatin may start to set up.

 

Now, with a clean whisk, whip the cream.

 

A soft peak is perfect. This texture is easiest to fold into the chocolate.

 

Scoop about a third of the whipped cream into the chocolate. Since the chocolate is kind of dense and heavy, this will help lighten it up. When we fold in the rest of the cream, it won’t deflate as much.

 

Scrape the sides and bottom of the bowl as you work, gently turning the mix in on itself.

 

Then add the rest of the whipped cream, and gently fold that in.

 

Ooooo, nice lines!

 

All folded. If yours looks a little more liquidy than mine, it’s ok — the mousse will be denser but will still taste good. It probably means your chocolate was on the warm side when you folded the cream, or the cream was whipped a little loose.

 

Pour the mousse into the waiting molds, filling them about halfway, without dripping on the insides of the molds. Otherwise when you’re ready to unmold the finished dessert, the sides will look messy. Put the whole tray in the freezer while you make the white chocolate mousse.

 

Make the white chocolate mousse:

Here are the ingredients. They’re pretty much the same as the dark chocolate mousse, except there’s less cream to whip.

 

The method is also the same as the dark chocolate mousse, and will feel like old hat by now.

Again, we bloom the gelatin.

 

Simmer the milk…

 

scrape in the gelatin, and let it dissolve.

 

The gelatin/milk mix gets poured over the white chocolate…

 

and we whisk it up into a smooth pool.

 

Whip the cream to soft peak stage and fold a third of it in to lighten. I just so happened to whip my cream a little too stiff as seen here.

 

It gave me some trouble when I tried to fold it in.

One lump, or two?

 

If this happens to you, take a whisk, and gently bang out the lumps with a few swift wacks. Again the mousse will be more dense because I beat some of the air out, but it’s still pretty good. Here’s my finished mousse.

 

It gets poured into the molds, most of the way up. Leave some space on top, about 1/8″ – 1/4″ for the chocolate glaze. Pop the tray back into the freezer while you make the glaze and garnish.

 

Make the garnish:

All we need are chopped chocolate and crunchy rice cereal

 

Melt the chocolate in a medium sized bowl by nuking it in a microwave. Start with 30 seconds, stir, then continue with 20 second intervals until it’s completely melted. Chocolate can scorch easily, so it’s best to do the melting in short spurts.

 

All melted.

 

Throw in the cereal…

 

…and work it around the bowl until it’s completely coated. There’s something very satisfying about doing this. If some of this mix makes it into your gullet, I’ll look the other way.

 

Spread it all out on a parchment-lined sheet pan, keeping it in little flat clusters. This way, the cereal bits touch each other, and can dry in chunks. Pop it in the fridge to set up. (This keeps in the fridge for weeks. Once the chocolate sets up, you can break this up and keep the pieces in a small plastic container.)

 

Whew! Lastly, let’s knock out the chocolate sauce/glaze:

Here’s the stuff.

 

Pour the heavy cream, corn syrup and oil into a microwave-proof cup and nuke until almost boiling (you might be able to see it gurgling in the cup), about 45 seconds. It will look curdled but pay it no mind. Stir it up to blend.

Pour over the chocolate and allow to sit for a minute to melt it all.

 

Whisk everything until completely smooth.

Here’s your chocolate sauce/glaze. Yup, it’s that easy. When it’s cold, it’s firm yet soft. When it’s warm, it’s liquid. Very versatile. (You can store this in the fridge for up to a week, but it will firm up. To bring it back to its liquid splendor, microwave it in 30-second intervals and stir between each nuking until it’s saucy.)

Wait until the sauce cools to lukewarm (so it doesn’t melt down the mousse), and carefully pour sauce onto the tops of your molds. It’s going to start setting almost immediately on contact from the cold, so work fast. Back into the freezer they go for at least 4 hours, to fully set. Once set, if you plan to keep them frozen for a while, be sure to wrap the tray very well to keep the cakes from absorbing strange freezer flavors.

 

The day you want to serve them, you can unmold the number you need. They come out of the rings more cleanly when frozen. First, roll them around in the palms of your hands for a minutes. The heat helps release them.

 

Then treat them like a push-pop, and gently press them out. They have a tendancy to slip out and land with a thud on your tray, so go slowly.

 

Here they are all lined up, army-style. Keep them uncovered in the fridge while they defrost. It probably takes a couple of hours to defrost something of this size. If you made a big cake, you may need another hour or two.

Don’t let them sit in the fridge for more than a day. The longer a gelatin-based dessert sits in the fridge, the more rubbery it becomes.

 

Right when you’re ready to serve, warm the chocolate sauce in the microwave for 30 seconds, give it a stir and pour some in your dish. Carefully place a cake in the center, handling it as little as possible to avoid getting grubby fingerprints all over it. Adorn the top and sides with some crunch pieces.

I couldn’t wait another minute.