Chocolate Mousse Cake

The Best Chocolate Mousse Cake

Light as air mousse with a deep, rich chocolate flavour on a fudgey brownie base. This chocolate mousse cake is seriously good.
Course Dessert
Cuisine American
Keyword cake, Chocolate, Mousse
Prep Time 1 hour
Cook Time 35 minutes
Chill Time 5 hours
Total Time 6 hours 35 minutes
Servings 12
Calories 551kcal
Author Elien


Brownie Base

  • 150 grams unsalted butter
  • 100 grams semi sweet chocolate
  • 1 cup sugar (225g)
  • 2 whole eggs
  • 1/4 tsp salt
  • 1 tsp vanilla
  • 1/2 cup cocoa powder (60 grams)
  • 1/2 cup all purpose flour (75grams)

Chocolate Mousse

  • 500 ml pouring cream
  • 1/3 cup sugar
  • 1 tsp instant coffee
  • 1 tsp gelatin
  • 2 tblsp water
  • 200 grams semi sweet chocolate

Chocolate Ganache Topping

  • 100 ml pouring cream
  • 100 grams semi sweet chocolate


Brownie Base

  • Preheat your oven to 180 degrees Celsius and grease and flour a 23cm springform cake tin. (You must be able to remove the bottom of the tin)
  • In a saucepan melt the butter and chocolate together over medium heat. Take off the heat and add in the sugar, then the eggs one at a time, beating well after each addition.
    Add in the vanilla, salt, cocoa and flour and mix well.
    Pour into the prepared tin and bake for 25 minutes. Allow to cool.
    Remove the brownie base from the tin then place it back in (this is to ensure you can remove the cake once the mousse is on top.) 
    Remove the sides of the tin and grease them with a little butter and dust with cocoa. Clip the tin back together and set aside. 

Chocolate Mousse

  • In a bowl add the water and the gelatin together, mix and leave it to sit.
    In a saucepan heat 100ml of the cream, the instant coffee and the sugar until just simmering. Turn off the heat and stir in the gelatin until dissolved.
    Add in the chocolate and let it sit for two minutes before mixing together into a smooth chocolatey liquid. Leave it to cool for five minutes.
    Whip the remaining 400ml of cream until soft peaks form, then add this in three lots, to the chocolate mix. Fold it in carefully and don't over mix.
    Spoon on top of the cold brownie base, smooth it down, cover with foil and chill for at least 4 hours (or overnight.)

Chocolate Ganache

  • Heat 100ml of cream until just simmering. Take off the heat and put in the chocolate. Allow to sit for a minute before whisking it together until glossy. Leave it to sit for 25 minutes and cool down.


  • Once the mousse has chilled for long enough, carefully run a knife along the edges and then remove the sides of the tin.
    Using a spatula or fish slice (or similar) carefully lift the cake off the tin and onto a cooling rack. Place the cooling rack onto a large oven tray (to catch ganache drips)
    Smooth the edges of the mousse to tidy it up, then pour over the chocolate ganache, allowing it to drip down the sides. Shave over extra chocolate if you like.
    Chill for another hour until the ganache has set, then serve.



Calories: 551kcal | Carbohydrates: 50.8g | Protein: 3.4g | Fat: 39.7g | Saturated Fat: 24.6g | Cholesterol: 124mg | Sodium: 153mg | Potassium: 162mg | Fiber: 3.5g | Sugar: 41.5g | Calcium: 40mg | Iron: 0.9mg