Indeed, this cake is a chocolate omelette; and with only 4 ingredients, it is super (ahem) healthy. Compared to some other things, at least. The cake is made with chocolate, a dozen eggs, a little butter and a little sugar. Most of the mousse-y batter is baked, but some is kept aside and spread lusciously on the top of the cake when it's done. (Caution - raw eggs can cause salmonella, so it might be better to keep the raw batter to people you don't mind too much about making sick).
The cake itself is light and fluffy, but apparently it becomes denser when chilled. I wouldn't know - my family polished it off the night it was made. That's how good it was.
Recipe Adapted From: Citrus and Candy; recipe originally from France by Damien Pignolet
Ingredients (26 cm (10 inch) cake - half this recipe fits a 20 cm (8 inch) springform tin)
360g bittersweet chocolate, roughly chopped
50g unsalted butter, softened
12 extra large eggs, separated
30g caster sugar (for whipping with yolks)
20g caster sugar (for egg whites)
Chocolate and cocoa for decoration
1. Preheat oven to 150 degrees C. Grease and line a 26-28cm springform tin. (Or a 20cm one, if you are making half a batch)
2. Melt the chocolate and mix in the butter.
4. Combine the egg yolk mixture with the melted chocolate and butter.
5. In a large, clean and dry bowl, whisk egg whites until soft peaks (make sure you don't overbeat, because the whites will become dry). Add the 20g caster sugar and beat until stiff peaks.
6. With a spatula or spoon, mix a quarter of the egg whites into the chocolate mix to lighten it. Add the chocolate mix to the rest of the egg whites and fold gently until combined.
8. Pour the rest of the batter into the prepared cake tin and bake for 30 minutes. It should still be moist in the centre - to test, lightly press your finger into the middle of the cake. The indentation should remain when you take your finger away.
9. Turn the cake out directly onto a serving plate. Remove the springform ring and base, let cool. The cake should collapse a bit, leaving a crater in the centre. Mine didn't really collapse - perhaps I baked it a bit too long, or maybe I shouldn't have flipped it. Oh well. It was yummy anyway.
10. Remember that leftover batter in the fridge? Scrape it out onto the top of the cake and spread around to the edges.