Go Back
–+ servings
5 from 2 votes

Chocolate Cake with Chocolate Mousse

By Britney
Prep: 3 hours 30 minutes
Cook: 30 minutes
Total: 4 hours
Servings: 15
a slice of chocolate cake with chocolate mousse on a cake stand lined with parchment paper.
Pin Print
This Chocolate Cake with Chocolate Mousse is a chocolate lover's dream! It features layers of moist chocolate cake with a shiny chocolate ganache filling and a rich chocolate mousse!

Equipment

Save this recipe!
Get this sent to your inbox, plus get new recipes from us every week!

Ingredients 

Chocolate Mousse

  • 1 tsp Gelatin
  • 1 tbsp (15 g) Cold Water
  • 4 Large (72 g) Egg Yolks
  • 2 cups (480 g) Heavy Cream, (divided)
  • 1/2 cup (100 g) Sugar
  • 2 1/4 cups (405 g) Semi-Sweet Chocolate Chips

Chocolate Cake

  • 2 cups (250 g) Cake Flour
  • 3/4 cups (65 g) Unsweetened Cocoa Powder
  • 2 tsp Baking Soda
  • 1 tsp Kosher Salt
  • 3/4 cup + 1 tbsp (180 g) Vegetable Oil
  • 5 tbsps (85 g) Salted Butter, (melted)
  • 2 1/2 cups (500 g) Sugar
  • 1 cup (240 g) Sour Cream, (room temperature)
  • 2 Large (100 g) Eggs, (room temperature)
  • 1 (18 g) Egg Yolk, (room temperature)
  • 1 tbsp (15 g) Vanilla Extract
  • 2 tbsp (30 g) Vinegar
  • 1 1/2 cups (360 g) Coffee, (hot)

Chocolate Ganache

  • 1 1/2 cups (270 g) Semi-Sweet Chocolate Chips
  • 3/4 cup (180 g) Heavy Cream
  • 3 tbsps (42 g) Salted Butter

Instructions 

Prepare the Creamy Chocolate Mousse 

  • Begin by making the chocolate mousse. Add gelatin and cold water to a small bowl or cup and gently mix together. Set aside while making the mousse. Add egg yolks, 1 cup of heavy cream, and sugar to a medium saucepan. Use a hand mixer to mix everything together for about 2-3 minutes, until bubbly/frothy. Place the pan on the stove over medium heat, stirring frequently for about 5-7 minutes, until slightly thickened.  1 tsp Gelatin 1 tbsp Cold Water 4 Large Egg Yolks 1/2 cup Sugar
  • Add in the semi-sweet chocolate chips and allow it to sit for about 1-2 minutes, then stir together until all of the chocolate is fully melted into the cream mixture. Add the gelatin and continue to stir until the gelatin is fully dissolved and the mixture is smooth, about 2-3 minutes. Remove from the heat and set aside. 2 1/4 cups Semi-Sweet Chocolate Chips
  • In a separate large bowl, use a hand mixer to beat the remaining 1 cup of heavy cream until stiff peaks form, about 5 minutes. Add the chocolate mixture to the whipped cream and continue to mix until combined (it may look soupy - this is normal). Cover with plastic wrap and place into the refrigerator to set for at least 3 hours.

Make the Chocolate Cake Layers

  • Preheat the oven to 350 degrees F. Spray 2 9-inch cake pans with nonstick baking spray or line with parchment paper. Set aside. 
  • In a large mixing bowl, whisk together vegetable oil, melted butter, sugar, sour cream, and vanilla extract until combined and smooth, about 1-2 minutes. Add in the eggs, egg yolk, and vinegar and continue to mix until combined, about 30 seconds. 3/4 cup + 1 tbsp Vegetable Oil 5 tbsps Salted Butter 2 1/2 cups Sugar 1 cup Sour Cream 1 tbsp Vanilla Extract 2 Large Eggs 1 Egg Yolk 2 tbsp Vinegar
  • To the same bowl, add cake flour, unsweetened cocoa powder, baking soda, and kosher salt. Gently fold together until a smooth batter forms, about 1 minute, then pour hot coffee on top. Let the coffee sit for about 30 seconds, then whisk together until a smooth batter comes together, about 30 seconds. 2 cups Cake Flour 3/4 cups Unsweetened Cocoa Powder 2 tsp Baking Soda 1 tsp Kosher Salt 1 1/2 cups Coffee
  • Divide the cake batter equally amongst two the cake pans and bake for 30-35 minutes, until a wooden skewer comes out with just a few crumbs. Allow the cakes to cool in the pan for 10 minutes, then turn over onto a wire rack to cool completely. 

Make the Chocolate Ganache

  • Add 3/4 heavy whipping cream to a heat-proof bowl and warm in the microwave for about 1 minute, until hot. Add chocolate chips and let it sit for 2 minutes. Stir together until the chocolate is fully melted into the cream (if it's not fully melted, place back into the microwave in 15 seconds increments, stirring between each time). 3/4 cup Heavy Cream 1 1/2 cups Semi-Sweet Chocolate Chips
  • Once fully melted, add butter and stir until the butter is melted into the chocolate. Set aside to cool and set. 3 tbsps Salted Butter

 Assemble the Cake 

  • Line a springform pan with parchment paper on the bottom and on the sides, making sure to have about 2 inches overhang OR use a acetate cake collar.
  • Place the one of the cooled cakes on bottom of the springform pan. Add a thin layer of the chocolate ganache and smooth into an even layer. Remove the chocolate mousse from the refrigerator and add half of the mousse on top of the chocolate ganache. 
  • Gently place the second cake layer on top of the mousse and smooth the remaining ganache on top, then add remaining chocolate mousse on top of the ganache. Place back into the refrigerator to set for about 4-6 hours. When you're ready to serve, remove from the springform pan and peel off the parchment paper (or cake collar if using). Garnish with chopped chocolate or chocolate curls. 

Notes

  • Chill thoroughly before serving: Let the finished cake set in the fridge for at least 4–6 hours (preferably overnight) so the mousse firms up and slices cleanly
  • Warm your knife to get clean cut slices: Dip a sharp knife in hot water and wipe it dry between slices for those clean, bakery-style cuts.
  • Make sure everything is at the right temperature: Make sure that the cakes have cooled completely prior to assembling the cake! This is crucial or else the mousse will melt! In addition, make sure that the chocolate mousse is set prior to adding to the cake or else it can seep into the cake and make it too mushy. 
  • Use a springform pan or cake ring to assemble the cake: Line the sides of the springform pan with acetate or parchment for super smooth edges when you unmold the cake.
  • Use good quality chocolate: The flavor of your mousse depends entirely on the chocolate you use. Pick a high quality semi-sweet chocolate (at least 60% cacao) or dark chocolate per your preference.

Nutrition

Calories: 672kcal, Carbohydrates: 61g, Protein: 7g, Fat: 46g, Saturated Fat: 22g, Polyunsaturated Fat: 8g, Monounsaturated Fat: 12g, Trans Fat: 0.3g, Cholesterol: 129mg, Sodium: 317mg, Potassium: 341mg, Fiber: 5g, Sugar: 43g, Vitamin A: 808IU, Vitamin C: 0.2mg, Calcium: 66mg, Iron: 3mg

Nutrition information is automatically calculated, so should only be used as an approximation.

Tried this recipe?Mention @BritneyBreaksBread or tag #BritneyBreaksBread!