1 Preheat the oven to 180 degrees, or 160 if using a fan oven. Grease a 20cm loose-bottomed or springform round cake tin and line the base with a disc of parchment paper.

2 Put the chopped chocolate into a heatproof bowl over a saucepan of simmering water, taking care to ensure that the bowl doesn't touch the water. Stir occasionally until the chocolate is completely melted then remove from the heat. Alternatively, melt the chocolate in the microwave in 30-second bursts.

3 Pour the olive oil into the melted chocolate in a steady stream, whisking all the time. Add half of the sugar, whisk well, then set aside to cool slightly.

4 Separate the eggs and put the whites into a spotlessly clean bowl. Begin to whisk the whites by hand or using an electric whisk and once foamy, add a tablespoon of the remaining brown sugar. Continue to whisk, adding a tablespoon of sugar at a time until all of the sugar is added and the whites have become voluminous with stiff peaks.

5 Whisk the egg yolks into the melted chocolate mixture and stir in the ground almonds and flaky sea salt. Using a large metal spoon, loosen the chocolate mixture by folding in a third of the egg whites, then gently fold the remaining egg whites into the mixture, taking care to avoid knocking out too much air.

6 Once all of the egg whites have been folded through and there are no remaining visible lumps of egg white, pour the mix into the prepared tin and bake in the preheated oven for 35-40 minutes.

7 Test the cake by inserting a skewer or knife into the centre. If it comes out clean, it is cooked. Bake for a further few minutes if needed.

8 Remove the cake from the oven and leave to cool in the tin for 10 minutes. Then remove from the tin, remove the parchment paper and leave to cool completely.

9 The cake will sink in the middle and crack around the edges, this is normal. Dust with icing sugar or cocoa powder and serve with crème fraiche.