Chocolate-Chestnut Mousse Cake

Merry Christmas!

I hope you guys are all having a safe and happy holiday season with your loved ones. I saw this recipe last month in Martha Stewart Living magazine and knew this one would be my Christmas dessert for the year.

It's a variation of an icebox cake. An icebox cake is a cake made primarily from whipped cream and chocolate wagers. You alternate layers of chocolate wafers with whipped cream and stack them together to form a cake. The cake is then left overnight in the refrigerator, hence the "icebox" reference in the name. The chocolate wafers absorb moisture from the whipped cream and the cookies soften as it sets in the refrigerator and take on a cake like consistency. It's also called a zebra cake because you can see the bands of chocolate and whipped cream when the cake is sliced. Taste-wise, it tastes like you're eating a giant Oreo cookie, dunked in milk.

Now the tricky part of this cake is finding chocolate wafers. I went to Ralphs, Vons and Rite Aid looking for these wafers but could only find the Nilla vanilla wafers. I thought about just substituting vanilla wafers instead but thought I'd do a search online for them. Turns out they are available on Amazon, but in packs of 12 or you can even make them from scratch. I only needed 24 chocolate wafers so both options didn't seem feasible to me. I then found out from a chowhound discussion board that these are sold at Ralphs and Vons but aren't in the cookie section. They are placed near the ice cream aisle with the ice cream cones and toppings or in the cracker section. Odd, I know. So I thought I'd give it one more shot and lo and behold, it was on the bottom aisle next to the rye crackers at Vons. Here are the infamous Nabisco Famous Chocolate Wafers, should you be on the look out for them as well.

They are thinner, lighter and larger than a Nilla Vanilla wafer. They taste like the cookie part of an Oreo.

This recipe also requires a jar of peeled, roasted chestnuts. I used two vacuumed packs of peeled and roasted chestnuts that you can find at most Asian markets. They are quite cheap too. I think I bought a pack for $1 or $2 each.

Chocolate-Chestnut Mousse Cake

adapted from Martha Stewart Living

Vegetable oil, for pan

1 jar (7.4 ounces) peeled, roasted chestnuts

1 cup whole milk

1 teaspoon of pure vanilla extract

1/4 cup plus 1 tablespoon light-brown sugar

pinch of coarse salt

3 large egg yolks

1 tablespoon cornstarch

1 teaspoon unsalted butter, room temperature

2 ounces bittersweet chocolate (preferably 61 cacao), melted and slightly cooled, plus more for shavings

1 1/2 cold heavy cream

24 chocolate wafer cookies (from 1 package)

Lightly coat the bottom of an 8-inch round cake pan with oil, and line the cake pan with plastic, leaving a 4-inch overhang. You are eventually going to invert the cake to serve, so the plastic helps to take the cake out easily and also to keep the mousse together.

Finely grind the chestnuts in a food processor. It's going to look grainy, don't worry.

Heat ground chestnuts, milk, 3 tablespoons of brown sugar and salt in a medium saucepan over medium-high heat, stirring occasionally, until bubbles form at edge.

Whisk together yolks, cornstarch and remaining 2 tablespoons of brown sugar in a medium heatproof bowl.
Slowly add hot chestnut mixture to the yolk mixture, whisking constantly. Return the chestnut and egg mixture to the pan and cook over medium-low heat. Whisk until thick, about 2 minutes. Transfer to a bowl of a mixer, add vanilla and butter and beat on medium speed until cool, about 5 minutes. I just did this by hand (one less bowl to clean later).

Stir half of the chestnut mixture into the melted chocolate.

Beat 1 1/4 cups of cream until soft peaks form.

Using a rubber spatula, gently fold half the whipped cream into plain chestnut mixture and the other half into chocolate-chestnut mixture.

Here's the chocolate mixture. You fold the chestnut and chocolate mixture with the whipped cream instead of stirring them together because you want to avoid the loss of air and fluffiness. Think of your rubber spatula as an oar or paddle on a boat. If you were kayaking, you would want blade of the paddle to be in contact with as much of the surface area of the water in order for the boat to move. In the same way, you want to drag the spatula through the mixture as well without causing too much agitation. Take your spatula and cut through the mixture, starting at the bottom and bring the spatula up and over, like you're folding a blanket. Sorry for the weird analogies today. =) You keep doing this and it will eventually incorporate together.

Next, you pour the chestnut mousse into the prepared pan. Cover with 12 chocolate wafers, working in a circular pattern. Top with chocolate-chestnut mousse and remaining 12 chocolate wafers. Fold plastic overhang over top to cover cake. Refrigerate overnight.Uncover cake; place a platter on top, flip and unmold. Remove the plastic around the cake. Beat the remaining 1/4 cup heavy cream until soft peaks form. Spread on top of cake. Garnish with chocolate shavings.
When you slice into it, you'll see the three layers of chocolate, chestnut and whipped cream.

The chocolate mousse is quite overpowering, so I think I might cut down on that next time. I would have preferred the chestnut flavor to come through a bit more, but with the chocolate mousse and the chocolate wafer, it lingered a bit more on the periphery, while the chocolate took center stage. At the same time, had it not been there, it might have just tasted like a chocolate cake, so the chestnuts were essential and helped balance out the flavors a bit more. I might try playing up the chestnuts a bit more next time. All in all, an excellent dessert and the best part is, it doesn't require any baking.