Dark Chocolate Mousse Cake

Chocolate lovers rejoice! Today I am sharing the recipe for my ultimate Dark Chocolate Mousse Cake! This is a fabulous recipe if you are having people round for dinner. It’s a real crowd-pleaser and everyone always seems to find room for a little slice – even if they were claiming to be full seconds before you brought it to the table. As you do all the cooking the day before, it’s a fantastic low-stress way to end the meal.

This dessert looks so beautiful everyone will think that you must have picked it up from the bakery, so it will knock their socks off when you tell them you made it at home.

This recipe isn’t at all difficult, though it does require a little time between each layer to make sure that they set, or cool before you add another. The ingredients are not extravagant, though do make sure to use good quality chocolate with at least 70% cocoa solids.

I’ve kept it very simple here, to allow the flavour of the chocolate to shine through, but there is certainly nothing stopping you adding a little liqueur to the mousse to kick things up a notch; a little orange or peppermint liqueur would compliment the chocolate perfectly. This recipe is also available in German! Click here to read.

Hopefully, you’ve all got a nice relaxing weekend planned, some of you are back to work, while others are enjoying some newfound freedom. Take care out there, look after yourselves, and most importantly, happy cooking!

Dark Chocolate Mousse Cake

Let me know if you try this recipe in the comments below, or using the hashtag #daysofjay on Instagram. Happy cooking!

Dark Chocolate Mousse Cake

Dark Chocolate Mousse Cake

Yield: 8
Prep Time: 45 minutes
Cook Time: 15 minutes
Chilling: 4 hours
Total Time: 5 hours

The ultimate dinner party dessert! Dark Chocolate Mousse Cake is the perfect way to round off a meal: moist chocolate cake, light and fluffy mousse, all topped with a layer of decadent chocolate ganache. Chocolate heaven!


for the base:

  • 75g plain flour
  • 50g sugar
  • 25g unsweetened cocoa powder
  • ¼ tsp baking soda, (sodium bicarbonate)
  • 75ml hot water
  • 2 Tbsp neutral oil, sunflower etc.
  • 1 tsp vinegar

for the chocolate mousse:

  • 2 sheets gold strength gelatine, 1.6g each (see note)
  • 200g dark chocolate, at least 70% cocoa solids, chopped
  • 500ml cream
  • 100g sugar

for the chocolate ganache:

  • 75g dark chocolate, chopped
  • 75ml cream
  • 1 tsp neutral oil, sunflower etc.


    Heat the oven to 180°C / 350°F / Gas 4. Line the base of a 20cm/8 in. springform cake tin with baking paper, then grease the base and the sides with butter.

    In a mixing bowl, whisk together the flour, sugar, cocoa and baking powder, ensuring there are no lumps - sift the mixture if necessary. Pour in the hot water, oil and vinegar, stir until smooth, then scrape into the prepared cake tin, smoothing the surface. Bake in the preheated oven for 10-12 minutes, until a skewer inserted in the centre of the cake comes out clean. Allow to cool completely in the tin.

    When the cake is cold, remove it from the tin, remove the baking paper from the bottom and place the cake on the serving plate or stand that you plan to use. Replace the outside of the springform around the cake, lining with cake acetate or baking paper if using (see note).

    To make the mousse, soak the gelatine leaves in a bowl of cold water for at least 5 minutes. Meanwhile, melt the chocolate in a large heat-proof bowl set over a pot of simmering water. When melted, remove from the heat and allow to cool slightly.

    In a small saucepan, combine 50ml of the cream with the sugar, and gently heat, stirring until the sugar is dissolved. Remove from the heat, then squeeze as much liquid out of the gelatine sheets as you can and stir into the hot cream. Pour the mixture into the melted chocolate and stir until smooth.

    In a mixing bowl, whip the rest of the cream until stiff peaks form - for this amount of cream it is best to use an electric beater. Scoop around a quarter of the cream into the bowl with the chocolate and stir to combine. At this point, the cream and chocolate will separate and you may think that everything has gone wrong. Don’t panic! Keep stirring until the mixture is smooth, it will come back together again.

    Using a spatula or a large spoon, fold the remaining cream under the chocolate mixture. Be gentle but thorough, you want to keep as much air in the mixture as possible, but also to ensure it is evenly mixed. Spoon the mousse on top of the cake, smooth the top and give it a little shake to even it out, then refrigerate for at least 2 hours.

    To make the ganache, put the chocolate into a small heatproof bowl. Heat the cream in a small saucepan until nearly boiling, then pour over the chocolate. Add the oil and allow to sit for 5 minutes. After 5 minutes, use a spoon (not a whisk) to beat the mixture until smooth. Allow to cool a further 5 minutes, then pour over the chilled cake, gently tilting to spread it evenly across the surface.

    Chill the cake for at least 2-3 more hours until set, better overnight. In hot weather or if your fridge is very full this is an important step! (see note)

    Before serving, remove the springform edge, carefully remove the cake acetate or baking paper (if using). If you like, top with some fresh berries. Use a sharp knife dipped in warm water to cut.


If you’ve ever wondered how bakeries and food bloggers get such lovely smooth sides on these sort of cakes, it is because they use cake acetate. This is a glossy plastic that is easy to remove from the outside of the cake and leaves a smooth finish. You can buy this online or from good kitchenware shops. You can also use baking paper - I find that it tends to get a bit soggy and leaves wrinkles on the finished cake - it still tastes good though! Alternatively, run a thin sharp knife around the outside of the cake before unmoulding.

Gelatine can be very different in different countries. The sheets I use in Europe weigh 1.6-1.7g each and come in 'Gold Strength'. As a general rule, 1 of these sheets = 1/2 tsp of powdered gelatine.

If you are in a real hurry, this cake can be frozen after you have added the ganache. It will need to defrost for ½ an hour or so before serving, depending on the heat of your kitchen. In hot weather keep the cake cool until just before serving.

Nutrition Information:
Yield: 8 Serving Size: 1
Amount Per Serving: Calories: 593Total Fat: 41gSaturated Fat: 23gTrans Fat: 1gUnsaturated Fat: 15gCholesterol: 85mgSodium: 44mgCarbohydrates: 51gFiber: 3gSugar: 37gProtein: 5g

Nutrition information is calculated automatically and isn’t always accurate.

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I don’t want to use gelatine. Is there an alternative?

While I haven’t experimented, there are vegetarian alternatives like agar-agar available.

I can’t get leaf gelatine, only powdered. How much should I use?

Sprinkle 1 tsp of powdered gelatine over 2 Tbsp cold water. Allow to swell for 5 minutes, then continue as per the recipe.

How long does Chocolate Mousse Cake keep?

Several days in the refrigerator, though it is best eaten in 2-3 days.

Dark Chocolate Mousse Cake Preparation

Follow the instructions carefully and you’ll end up with the most gloriously light and fluffy chocolate mousse!

Dark Chocolate Mousse Cake Preparation

Dark Chocolate Mousse Cake

Leave it plain or decorate with fresh berries. It’s delicious either way.


Looking for more CHOCOLATE recipes? Why not try:

Easy Double Chocolate Fondants
Jay Wadams
Jay Wadams

Jay Wadams is a cookbook author, food photographer and Le Cordon Bleu Gastronomy and Nutrition graduate. Based in Italy 🇮🇹 Germany 🇩🇪 and Australia 🇦🇺.

Articles: 333


    • Hi Julian, yes you can! Powdered agar agar is fairly much a 1/1 ratio with gelatine, though it depends on the brand – it can be a little stronger. The agar agar packet should have a comparison on it! I’d love to know how you get on! J. UPDATE: 10g powdered agar agar is equivalent to 6 sheets gelatine, so in this recipe you would need around 3g agar agar – hope that helps!

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