Let’s all just take a moment to appreciate Delia Smith. The woman has managed to make a chocolate mousse cake that is heading towards healthy – by chocolate cake standards in any case. It is gluten free which must tick a healthy box, has cream – that’s your calcium and good quality chocolate – that’ll be your antioxidants or something made up like that.
Mum has been making this one for forever. It was originally meant to be a swiss roll but mum side-stepped that tricky rolling business by making it as a 9inch round cake instead. Smart.
Sister #4, back in the day, developed a frosting/ icing for it, as the original has none and what chocolate cake is worth a damn without icing? None. The addition of whipped cream to the icing makes it lovely and light and quite unlike most other chocolate cake toppings.
As for the recipe, this is one that I really would encourage you to abide by my timings, especially for the filling.
You can store this cake, unlike most, in the fridge but that is only because it has fresh cream in it.
Off we go.
Oven temperature 180 Celsius
Chocolate Sponge Cake;
Eggs (separated) 6
Caster sugar 110g
Cocoa powder 50g
Chocolate Mousse Filling;
Dark chocolate 225g
Water 2 tablespoons
Eggs (separated) 2
You’ll also need 400ml or so of cream to fill the cake
Chocolate Mousse Frosting;
The remnants from the filling bowl, cocoa powder, icing sugar and some whipped cream
Preheat the oven and line two 23cm round tins, check out how to do that here.
Now. Put the six egg whites into one big mixing bowl and the six egg yolks into a second large mixing bowl. Add the sugar to the egg yolks and beat thoroughly to combine and then beat in the cocoa.

Whisk up the egg whites to stiff peaks.
Add a third of the egg whites into the cocoa-eggy bowl and mix to combine. Then tip in the rest of the egg whites and fold VERY gently. Don’t know how to fold? Let there be no panic. Click here to see a short video of how to fold.

Once that’s done, pour it carefully into the prepared tins. It’s a fierce straightforward cake really. Now put them into the oven for about 20-25mins. They’ll obviously be good and brown but apart from that they should be just springy when they’re baked.
The cakes will come away from the side and look a bit rustic but embrace it.
To the filling. Put the chocolate and water in a heatproof bowl over a pan of barely simmering water (you can see the set up here). Let it melt away, only stirring when the temptation becomes too much.
Once melted, let it cool down slightly – top photo of my fancy collage.

Beat in the two egg yolks – middle photo.
Whisk up the two egg white to firm peaks and then add one third of them into the egged chocolate mixture. Then fold in the remaining egg whites CAREFULLY – bottom photo. Cover the bowl with cling film and put it in the fridge for about 2hrs. This is where I am telling you to pay attention. Don’t use the mousse till it’s firmish but definitely do not refrigerate for much more than 2hrs or it will be wholly unspreadable and a pain in the arse to work with.
Whip your cream.
To begin the construction;
- Peel the baking parchment of both of the sponges. Pop one down on a nice serving plate.
- Spread all but about 1 tablespoon of mousse filling onto the sponge
- Spread all but about 3 tablespoons of the whipped cream onto the mousse filling
- Place the second sponge, bottom/flat side up, on top of the cream

Now make your icing. As with most all of my icing recipes it’s up to yourself. Make it in the almost empty mousse bowl. Put in about 6 tablespoons of icing sugar, then about 2 tablespoons of cocoa powder and then a substantial dollop of the whipped cream.
Beat it all together and add in more icing sugar if it’s too runny and more cream if it’s too thick.

Now spread it all over the top of the naked cake. There should be lots and it should look very tasty indeed.