

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.
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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.
FREQUENTLY ASKED QUESTIONS
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.
Follow the instructions carefully and you’ll end up with the most gloriously light and fluffy chocolate mousse!
Leave it plain or decorate with fresh berries. It’s delicious either way.
Dark Chocolate Mousse Cake
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!
Ingredients
for the base:
- 75 g plain flour
- 50 g sugar
- 25 g unsweetened cocoa powder
- ¼ tsp baking soda, (sodium bicarbonate)
- 75 ml 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)
- 200 g dark chocolate, at least 70% cocoa solids, chopped
- 500 ml cream
- 100 g sugar
for the chocolate ganache:
- 75 g dark chocolate, chopped
- 75 ml cream
- 1 tsp neutral oil, sunflower etc.
Instructions
- PREPARE: Heat oven to 200°C / 400°F (180°C fan). Line the base of a 20 cm springform cake pan with baking paper and lightly grease the sides.
- MAKE SPONGE: In a stand mixer, beat the eggs, caster sugar, vanilla sugar and salt on high for 5 minutes, until thick and pale. Drizzle in the oil during the final minute of mixing. Sift together the flour, cocoa and baking powder. Sift over the egg mixture and gently fold in with a spatula until just combined.
- BAKE: Pour the cake batter into the prepared pan, smooth the top and tap the pan on the bench to release air bubbles. Bake for 10–12 minutes, until springy. Cool completely in the cake pan.
- PREPARE TIN: When cool, remove the sponge, peel off the paper and place on a serving plate. Reattach the springform ring and line the inside with cake acetate.
- MAKE MOUSSE: Soak gelatine in cold water for 5 minutes. Meanwhile, melt the chocolate in a heatproof bowl over a pot of simmering water. Set aside to cool slightly. In a small saucepan, heat 50 ml of the cream with the sugar until dissolved. Remove from the heat, squeeze out the gelatine and stir into the warm cream. Stir the cream mixture into the melted chocolate until smooth.
- WHIP CREAM: Whip the remaining cream to stiff peaks. Stir a spoonful into the chocolate to loosen—it may look split but will smooth out. Gently fold in the rest of the cream.
- FILL AND CHILL: Spoon mousse over the sponge, smooth the top and chill for at least 2 hours.
- MAKE GANACHE: Place chocolate in a small bowl. Heat cream until just boiling, pour over the chocolate, add the oil and let sit for 5 minutes. Stir gently until smooth. Cool for a few minutes, then pour over the chilled mousse. Tilt to spread evenly. Chill 2–3 hours or overnight.
- SERVE: Run a knife around the edge, remove the springform ring and peel off the acetate. Slice with a warm knife. Garnish with berries if you like.
Notes
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.
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Nutrition
Serving: 1Slice | Calories: 593kcal | Carbohydrates: 51g | Protein: 5g | Fat: 41g | Saturated Fat: 23g | Polyunsaturated Fat: 15g | Trans Fat: 1g | Cholesterol: 85mg | Sodium: 44mg | Fiber: 3g | Sugar: 37g
Tried this recipe?I’d love to hear how it went! Please leave a review or a star rating and let me know how it was! Use the hashtag #daysofjay on Instagram so I can see your delicious creations.

About the Author
Jay Wadams is a cookbook author, food photographer, and graduate of Le Cordon Bleu in Gastronomy and Nutrition.
Based in Italy 🇮🇹 Germany 🇩🇪 and Australia 🇦🇺.
Thanks for recipe. My question: Can I replace gelatin with agar agar? If yes, what is the ratio?
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!
I love it!!!
——- Thanks so much Julian! J.