Triple Chocolate Mousse Cake

updated Jan 31, 2024
christmas
Triple Chocolate Mousse Cake Recipe

A bowl of chocolate mousse is a decadent treat, but a double-layered chocolate mousse cake with a cookie crust is next level.

Serves8

Makes1 (9-inch) cake

Prep15 minutes

Cook20 minutes

Jump to Recipe
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angled shot of a piece of triple chocolate mousse cake topped with raspberries.
Credit: Photo: Ryan Liebe ; Food Stylist: Brett Regot

A bowl of chocolate mousse is a decadent treat, but a layered chocolate mousse cake with a cookie crust is next-level. There are many varieties of chocolate mousse cake. Some have chocolate cake crusts rather than the cookie crust; others are chocolate cake layered with a mousse frosting. But we think our double-layered chocolate mousse cake is one of the best.

This mousse cake is set in the refrigerator rather than baked and is served cold. The texture and flavor are dreamy — an ethereal light and fluffy chocolate dessert.

Credit: Photo: Ryan Liebe ; Food Stylist: Brett Regot

What’s in Triple Chocolate Mousse Cake?

To add contrasting flavor and keep the thick mousse layer from becoming too monotonous, we developed an easy method for creating a two-toned mousse.

  • Milk chocolate layer: The milk chocolate layer is slightly sweeter and more subdued.
  • Dark chocolate layer: This richer layer is made with dark chocolate. Dark chocolate balances out the sweetness of the milk chocolate layer with its intense chocolate flavor.
  • Oreo crust: A classic no-bake Oreo crust that’s sure to hit the spot for chocolate fans.

How to Make Light and Airy Chocolate Mousse

There are many ways to get that beautiful light and airy texture in chocolate mousse. Traditionally in French cooking, mousse is thickened with both egg whites and yolks. While it’s a decadent and absolutely wonderful way to prepare mousse, the procedure is a bit more complicated and the eggs are usually raw, which means not everyone will be comfortable digging in. Instead, we opted for folding melted chocolate and gelatin into whipped cream.

  • Use gelatin powder.  Incorporating gelatin powder into the chocolate mixture, along with folding in whipped cream gives the chocolate mousse a light and airy texture. Gelatin powder also stabilizes and sets the chocolate mousse when refrigerated.
  • Allow the chocolate mixture to cool. Make sure the dark and milk chocolate mixtures are cooled to room temperature before folding in the whipped cream, otherwise the whipped cream will melt.
  • Gently fold the whipped cream into the chocolate. Folding is a mixing technique where you gently combine two ingredients without stirring. Using a flexible spatula, swipe the whipped cream down under the chocolate, then scoop it up and over until just combined. It’s a swoop and tuck motion that’s used in desserts like classic chocolate mousse and sponge cake.
Credit: Photo: Ryan Liebe ; Food Stylist: Brett Regot

How to Get the Perfect Slice of Triple Chocolate Mousse Cake

Delicate and light, the perfect slice of chocolate mousse cake is only achieved by cutting it with a warm knife. Sure, you can get a “good enough” slice without warming the knife, but here is how to get one that looks just like our pictures.

  1. Fill a tall bowl or glass with hot water. It should be big enough to fit the blade of a chef’s knife.
  2. Place the blade of the knife in the hot water. Keep it in there for a good 10 to 30 seconds until the blade is hot.
  3. Wipe excess water off with a towel and slice into the cake. In between each cut, return the knife to the warm water and wipe it off with a towel again before going in to slice.

Triple Chocolate Mousse Cake Recipe

A bowl of chocolate mousse is a decadent treat, but a double-layered chocolate mousse cake with a cookie crust is next level.

Prep time 15 minutes

Cook time 20 minutes

Makes 1 (9-inch) cake

Serves 8

Nutritional Info

Ingredients

  • Cooking spray

  • 4 tablespoons

    (1/2 stick) unsalted butter

  • 20

    Oreo cookies

  • 4 tablespoons

    cold water, divided

  • 3 teaspoons

    unflavored powdered gelatin, divided

  • 8 ounces

    dark chocolate chips (1 1/4 cups)

  • 8 ounces

    milk chocolate chips (1 1/4 cups)

  • 4 cups

    cold heavy cream, divided

  • 2 tablespoons

    dark unsweetened cocoa powder

  • 1/2 cup

    powdered sugar

  • 2 teaspoons

    vanilla extract

  • 1/4 teaspoon

    kosher salt

  • 1 pint

    fresh raspberries

Instructions

  1. Coat a 9-inch round springform pan with cooking spray. Place 4 tablespoons unsalted butter in a small microwave-safe bowl and microwave on high until just melted, 20 to 30 seconds.

  2. Place 20 Oreo cookies in a food processor fitted with the blade attachment. Pulse until finely chopped, about 10 (1-second) pulses. Add the butter and pulse until combined, about 8 (1-second) pulses. Transfer to the pan and press evenly into the bottom with your fingertips or the bottom of a measuring cup. Refrigerate while you make the chocolate layers.

  3. Place 2 tablespoons of the cold water in a small bowl and sprinkle with 1 1/2 teaspoons of the powdered gelatin. Place the remaining 2 tablespoons cold water in a second small bowl and sprinkle with the remaining 1 1/2 teaspoons powdered gelatin. Let both sit to hydrate for at least 5 minutes.

  4. Place 8 ounces dark chocolate chips in a medium or large heatproof bowl. Place 8 ounces milk chocolate chips in a second medium or large heatproof bowl.

  5. Bring 1 cup of the heavy cream to a simmer in a small saucepan over medium-high heat. Remove the pan from the heat. Add one of the hydrated gelatin portions and whisk until smooth and the gelatin is dissolved. Pour over the milk chocolate chips and stir until the chocolate is melted and the mixture is smooth and combined. Let cool until room temperature, about 20 minutes.

  6. Wash and dry the saucepan. Add 1 cup of the heavy cream into the same saucepan and bring to a simmer over medium-high heat. Remove the pan from the heat. Add the remaining hydrated gelatin and 2 tablespoons dark cocoa powder, and whisk until smooth and the gelatin and cocoa powder are dissolved. Pour mixture over the dark chocolate chips and stir until the chocolate is melted. Let cool until room temperature, about 20 minutes.

  7. Place the remaining 2 cups cold heavy cream, 1/2 cup powdered sugar, 2 teaspoons vanilla extract, and 1/4 teaspoon kosher salt in a large bowl if using an electric hand mixer (or stand mixer fitted with the whisk attachment). Beat on medium-high speed until firm peaks form, about 3 to 4 minutes.

  8. Divide the whipped cream between the dark and milk chocolate mixtures (about 2 cups per bowl). Fold the whipped cream into the dark chocolate mixture with a flexible spatula just until combined and no streaks remain. Dollop into the crust and smooth into an even layer. Refrigerate until just set, about 20 minutes. Meanwhile, fold the cream into the milk chocolate mixture and let sit at room temperature.

  9. Dollop the milk chocolate mixture over the slightly chilled dark chocolate layer and smooth into an even layer. Cover and refrigerate until the cake is fully set, at least 4 1/2 hours and up to 3 days.

  10. To serve, run an offset spatula around the edges of the pan to loosen, then remove the sides of the pan. Top with 1 pint fresh raspberries. Slice with a chef’s knife and serve cold. For the cleanest cuts, use a knife run under warm water and wiped dry for each cut.

Recipe Notes

Make ahead: The cake can be made, covered, and refrigerated up to 3 days ahead.

Storage: Leftover cake can be wrapped and refrigerated for up to 1 week.