Start with the recipe for flourless chocolate cake from The Primrose Bakery Cookbook. When you add the melted butter and chocolate to the egg yolks I urge you to wait for it to cool down, or you will curdle the yolks. When the recipe says to line the tray with baking paper, do as they say, or you’ll be scraping the cake out of the tin with a spatula. Check your oven is not too hot if you don’t want the whole thing to souffle up, burn on one side, and then sink to a quarter of its height.
That said, the bits that weren’t burnt tasted great and my newly thrifted Paris plates are so pretty they kind of distracted me from the burnt bits.