Mary Berry Chocolate Truffle Mousse Cake Recipe​

Mary Berry Chocolate Truffle Mousse Cake is a classic British dessert featuring a light cocoa sponge topped with a rich dark chocolate and double cream mousse. This indulgent treat uses high-quality cocoa solids and whisked eggs to achieve its signature airy texture.

If you do nothing else, make sure the melted chocolate is tepid before you add it to the cream. If it’s too hot, the cream will melt into a puddle, and if it’s too cold, you’ll end up with hard lumps of chocolate instead of a smooth mousse. I learned this the hard way when I rushed the cooling process and ended up with a grainy mess that wouldn’t set properly.

The sponge base relies entirely on the air you whisk into the eggs and sugar since there’s no butter to help it rise. Using a metal spoon to fold in the flour is the only way to keep that volume so the base stays light enough to balance the heavy truffle topping. It’s the cake I always bring out for birthdays because it looks like it came from a professional bakery but only takes a few steps to put together.

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Mary Berry Chocolate Truffle Mousse Cake Ingredients

Chocolate Sponge Base

• 4 large free-range eggs
• 100g (3.5oz) caster sugar
• 65g (2.3oz) self-raising flour
• 40g (1.4oz) cocoa powder

Chocolate Truffle Mousse

• 200g (7oz) dark chocolate (minimum 70% cocoa solids), broken into pieces
• 450ml (16fl oz) double cream

Decoration

• 1 tsp cocoa powder, for dusting
• 25g (1oz) chocolate shavings

How To Make Mary Berry Chocolate Truffle Mousse Cake

1. Heat the oven: Set the temperature to 180°C (350°F/Gas Mark 4) and grease a 20cm (8in) deep springform tin before lining the base with greaseproof paper.
2. Whisk the eggs and sugar: Put the eggs and caster sugar into a large bowl and beat with an electric whisk for about 5 to 8 minutes until the mixture is thick and pale. Stop when the whisk leaves a trail on the surface that stays visible for three seconds.
3. Mix in the dry ingredients: Sift the self-raising flour and cocoa powder over the egg mixture and use a large metal spoon to gently fold them together. Stop as soon as you see no more streaks of flour to keep as much air in the batter as possible.
4. Bake the sponge: Pour the mixture into the prepared tin and bake for 20 to 25 minutes until the cake has risen and the top feels springy when you press it lightly. Let the cake cool in the tin completely so it doesn’t shrink away from the sides.
5. Melt the chocolate: Place the dark chocolate pieces in a bowl over a pan of gently simmering water and stir until smooth. Take the bowl off the heat and leave it to cool until it feels just warm to the touch.
6. Whip the cream: Pour the double cream into a cold bowl and whisk it until it forms soft peaks that just hold their shape. Do not overbeat it or the cream will turn stiff and make the mousse difficult to spread.
7. Fold the mousse together: Pour the tepid melted chocolate into the whipped cream and use a spatula to gently mix them until the colour is even. Work quickly so the chocolate doesn’t set into spots before it’s fully combined.
8. Assemble and set: Spread the mousse over the cooled sponge while it’s still in the tin and level the top with the back of a spoon. Put the cake in the fridge for at least 4 hours or overnight until the topping is firm.
9. Remove and decorate: Run a thin knife around the inside edge of the tin before opening the springform clip and lifting the cake out. Dust the top with cocoa powder and scatter the chocolate shavings over the centre before cutting into slices.

Recipe Tips

• Use a metal spoon for folding. Wooden spoons are too heavy and have a wide surface area that pops the air bubbles you’ve worked hard to whisk into the eggs. A thin metal spoon cuts through the mixture cleanly without deflating the sponge base.
• Check the chocolate temperature with your finger. The melted chocolate should feel roughly the same as your body temperature before you add it to the cream. If it feels hot, wait another five minutes, or the heat will break the structure of the whipped cream.
• Grease the sides of the tin thoroughly. Even with a springform tin, the mousse can stick to the metal as it sets. Applying a thin layer of butter or neutral oil to the sides before adding the mousse helps the cake slide out with a smooth, professional edge.
• Make this a day in advance. The mousse needs several hours to reach the right consistency, and the flavours actually improve after sitting. It’s the best way to ensure the cake is stable enough to slice cleanly without the middle sagging.
• Store your bowl in the fridge. If your kitchen is warm, chill the bowl and the whisk beaters before whipping the double cream. This keeps the fat stable and helps the cream reach the soft peak stage faster without curdling.

What To Serve With Chocolate Truffle Mousse Cake

A handful of fresh raspberries or sliced strawberries provides a sharp contrast to the dense chocolate layers. You could also add a spoonful of extra thick single cream or a scoop of vanilla bean ice cream to balance the intensity of the dark cocoa.

The cake is quite rich, so a cup of strong black coffee or a glass of cold milk works well. For a more formal dessert, serve it alongside a small glass of dessert wine or a few sprigs of fresh mint.

How To Store Chocolate Truffle Mousse Cake

• Fridge: Keep the cake in an airtight container in the fridge for up to three days. The mousse contains double cream, so it must stay chilled and should not sit out at room temperature for more than an hour.
• Reheat: Do not reheat this cake as the mousse will melt into a liquid. Serve it directly from the fridge or let it sit on the counter for 10 minutes if you prefer the sponge a little softer.
• Freeze:Wrap the entire cake or individual slices tightly in clingfilm and a layer of aluminium foil for up to one month. Thaw the cake slowly in the fridge overnight before serving to maintain the texture of the chocolate topping.

Mary Berry Chocolate Truffle Mousse Cake Nutrition Facts

Per serving (1 of 12):

• Calories 342
• Protein 5g
• Fat 26g
• Carbohydrates 22g
• Sugar 18g
• Sodium 65mg

FAQs

Can I use milk chocolate for the mousse instead?

No, the recipe relies on the high cocoa butter content of dark chocolate to set the mousse firmly. Milk chocolate has more sugar and fat, which results in a runny topping that won’t hold its shape when sliced.

Why did my sponge base turn out flat?

This usually happens if you didn’t whisk the eggs and sugar for long enough or if you were too heavy-handed when folding in the flour. Make sure the egg mixture is thick enough to hold a trail before you stop whisking.

How do I get clean slices of Mary Berry Chocolate Truffle Mousse Cake?

Dip a long, sharp knife into a jug of hot water and wipe it dry between every single cut. The heat from the metal will glide through the chilled chocolate mousse without dragging the topping into the sponge.

Can I use a different size tin for this recipe?

It is best to stick to a 20cm (8in) tin because the mousse quantities are calculated to fill that specific volume. A larger tin will result in a very thin mousse layer, while a smaller tin may overflow before the cake is set.

Is it possible to make this gluten-free?

Yes, you can swap the self-raising flour for a gluten-free self-raising blend. Since the structure of this cake comes mostly from the whisked eggs rather than gluten, the texture remains very similar to the original version.

Try More Recipes:

• Mary Berry Chocolate Fairy Cakes​ Recipe
• Mary Berry Chocolate Chip Loaf Cake​ Recipe
• Mary Berry Vegan Chocolate Cake​ Recipe