Chocolate Mousse Cake
Servings Prep Time
8-10 servings 90minutes plus chilling
Cook Time
16minutes
Servings Prep Time
8-10 servings 90minutes plus chilling
Cook Time
16minutes
Chocolate Mousse Cake
Ingredients
Flourless Fudge Cake (Bottom Layer)
  • 6tablespoons unsalted buttercut into 6 pieces
  • 7ounces bittersweet chocolate*finely chopped
  • 4 large eggsseparated
  • 1 1/2teaspoons vanilla extract
  • 1/2teaspoon baking powder
  • 1/8teaspoon cream of tartar
  • 1/8teaspoon salt
  • 1/2cup packed light brown sugar
Chocolate Mousse (Middle Layer)
  • 1 1/2teaspoons unflavored gelatin
  • 2tablespoons water
  • 8ounces bittersweet chocolate*roughly broken into pieces
  • 4ounces semi-sweet chocolateroughly broken into pieces
  • 1teaspoon vanilla extract
  • 1/4teaspoon salt
  • 2cups heavy creamdivided
  • 2 whole pasteurized eggs
  • 1/4cup granulated sugar
  • 4 pasteurized egg whites only
Chocolate Ganache (Top Layer)
  • 6ounces bittersweet chocolate*roughly broken into pieces
  • 3/4cup heavy cream
  • 2tablespoons corn syrup
Instructions
Flourless Fudge Cake (Bottom Layer)
  1. Preheat oven to 325 degrees F. Line the bottom of a 9-inch springform pan that is at least 3 inches high with parchment paper. Spray the bottom parchment and inside of the pan with cooking spray; set aside.
  2. Melt the chocolate and butter together. You can either do this in a double boiler on the stove by: placing the chocolate and butter in a large heatproof bowl, set over a boil of gently simmering water, and stirring until melted and smooth. Or you can do this in the microwave by: heating the chocolate and butter in a microwave-safe bowl in 30-second intervals, stirring in between, until the chocolate and butter are melted and smooth.
  3. Let melted chocolate cool for 5 minutes then whisk in egg yolks, vanilla and baking powder; set aside.
  4. In a stand mixer fitted with the whisk attachment, beat the egg whites, cream of tartar and salt at medium speed until frothy, about 30 seconds. Add ¼ cup brown sugar and beat to combine, then add the remaining brown sugar and beat at high speed until soft peaks form, scraping down the sides halfway through. (Soft peaks means when you remove the whisk, a peak is just starting to hold and then droop after a second.)
  5. Using a rubber spatula, fold the beaten egg whites into the chocolate mixture in thirds until no white streaks remain. Transfer the batter to the prepared springform pan, tap on the counter a few times, then smooth the top with a spatula.
  6. Bake at 325 degrees F until the cake has risen in the center and the edges are set (a toothpick will NOT come out clean), 16-20 minutes. Transfer the pan to a wire rack to cool completely, about 1 hour. The cake will collapse slightly as it cools. You can begin making the mousse 45 minutes after cooling.
  7. Once the cake has cooled, temporarily remove the springform pan. Snuggly encircle the cake with parchment paper that reaches about 1 inch above the edge of the springform (you can tape the parchment to itself.) Re-place the springform pan and re-clasp. Set aside.
Chocolate Mousse (Middle Layer)
  1. Add unflavored gelatin to a microwave safe bowl then pour the cold water over top; let stand for 5 minutes. Transfer the gelatin mixture to the microwave and microwave for 15 seconds. Stir the mixture, then set aside to cool.
  2. Add chocolate to food processor and finely chop. Add vanilla and salt and pulse a few times to combine. Transfer 1 cup heavy cream to a microwave safe measuring cup/bowl and microwave until boiling, about 2 1/2 minutes.
  3. With processor running, gradually pour hot cream through feed tube and process until chocolate is melted and smooth. Transfer mixture to a large bowl and refrigerate. Once room temperature (don’t let it cool completely), whisk in 2 whole eggs. (See notes if you don’t have a food processor.**)
  4. Meanwhile, in another clean mixing bowl, beat the remaining 1 cup heavy cream with sugar on medium-high speed with a handheld mixer until soft peaks form. Turn to low and slowly pour in the gelatin mixture. Mix until combined then increase the speed to medium and continue mixing until stiff peaks form; set aside. (If your gelatin has hardened, microwave to liquify again and cool.)
  5. Add 4 egg whites to the clean bowl of your electric mixer fitted with the whisk attachment. Whip until stiff peaks form.
  6. Gently fold one third of the beaten egg whites into the chocolate mixture at a time, don’t stir or the egg whites will deflate. Gently fold in the whipped cream until completely combined.
  7. Pour mousse over cooled cake and smooth into an even layer and cover with plastic wrap. Chill for 2 hours up to 24 hours. You can add the ganache at any point between the 2 and 24 hours.
Chocolate Ganache (Top Layer)
  1. Add heavy cream to a large microwave safe bowl. Microwave until just boiling, about 2 minutes. Remove from microwave and add chopped chocolate. Let stand 1 minute, then whisk vigorously until ganache is melted and smooth. Whisk in corn syrup.
  2. OR to make ganache in food processor: Add chocolate to food processor and finely chop. Transfer heavy cream to a microwave safe measuring cup/bowl and microwave until boiling about 2 minutes. Pour hot cream evenly over the chocolate in the food processor and let stand for 1 minute. Cover then process until chocolate is melted and smooth. Pour in corn syrup and pulse to combine.
  3. Pour ganache over chilled mousse and spread into a smooth layer. Chill for 30 minutes or until ready to serve.
  4. Remove springform pan and parchment paper. Garnish with raspberries, shaved chocolate and serve.
Recipe Notes

**Chocolate Mousse Step 2-3:  I love completing these step in my food processor because it takes minutes, but you can also complete it without a food processor, by adding hot heavy cream to finely chopped chocolate in a microwave bowl. Let stand 1 minute, then whisk vigorously until melted and smooth then add vanilla and salt; refrigerate. Once room temperature (don’t let it cool completely), whisk in 2 whole eggs.

Tips and Tricks

  • I recommend pasteurized eggs.  The chocolate mousse uses raw eggs which are not recommended for those with a compromised immune system, are pregnant or elderly due to the risk of salmonella.  If you fit any of these categories or would like more peace of mind, I suggest using pasteurized eggs. Pasteurized eggs are just a little more expensive but pasteurization destroys any potential bacteria and viruses so they are completely safe to eat raw.  The FDA says: “For recipes that call for eggs that are raw or undercooked when the dish is served — like Caesar salad dressing and homemade ice cream — use either shell eggs that have been treated to destroy Salmonella, by pasteurization or another approved method, or pasteurized egg products.”

  • Do I have to use corn syrup?  Corn  syrup makes the chocolate ganache extra smooth, keeps it flexible when it sets and keeps it shiny even after being refrigerated.  Without corn syrup, the ganache will not boast these properties.
  • Use good quality chocolate bars. The chocolate is the star of the show, so be sure to invest in some good quality chocolate baking bars. I recommend Ghirardelli 60 percent Cacao Bittersweet Chocolate. Any other chocolate is likely to produce drier results. 
  • Use bittersweet chocolate. If you use all milk or semi-sweet chocolate in this recipe the cake will be far too sweet.
  • Gently melt chocolate.  Whether you melt the chocolate for the fudge cake layer in the microwave or double broiler, do it gently/gradually so the chocolate doesn’t break, separate or scorch. 
  • Cool chocolate until barely warm.  Once you’ve melted the chocolate for the fudge cake layer, cool it until it is barely warm – not hot and not cold.   Too warm and the eggs will scramble, too cool and the chocolate will seize up when you add the other ingredients.
  • Separate eggs when cold, but whip at room temp.  Eggs separate easiest when they are cold straight out of the refrigerator, however, egg whites will whip more easily when they are room temp.  So, separate the eggs first and then let the egg whites sit at room temp for several minutes before whipping.
  • Whip eggs whites in a clean bowl.  Egg whites will not whip effectively if there is residual fat in the mixing bowl or bowl beaters, so make sure you are using very clean, dry equipment.
  • Don’t over-bake bottom fudge cake. A toothpick will NOT come out clean in the center of the fudge cake when it’s done.  The cake is meant to walk the fine line between gooey and fudgy.   The cake is done when the center reads 200°F on an instant-read thermometer.
  • Gently fold egg whites and whipped cream into mousse.  Gently folding instead of stirring will keep the mousse light and fluffy and prevent the eggs from deflating.
  • Let each layer chill. This triple Chocolate Mousse Cake recipe requires some patience, but it’s vital that you let the fudge cake layer cool completely after it’s done baking. Then, the cake should be left to chill in the fridge after the first mousse layer has been added, and so on. 

How to Store 

This Chocolate Mousse Cake must be stored in the fridge. You can store the cake in the springform pan with plastic wrap on top until ready to serve or store it directly on a serving plate, covered.  Chocolate Mousse Cake will last up to 4 days.

How to Freeze 

Yes! You can absolutely freeze Chocolate Mousse Cake! Tightly wrap in plastic wrap followed by double layers of foil. Freeze for up to two months. When ready to enjoy, thaw in the refrigerator overnight, do NOT attempt to heat it in any way.