Melt the chocolate

Add the olive oil and cocoa powder

Stir to combine, making sure there are no lumps

Preheat your oven to 170°C. Grease a 22cm springform tin with a little oil and line the base with baking parchment.

Measure and sift the cocoa powder into a bowl or jug and whisk in the boiling water until you have a smooth, chocolatey, still runny (but only just) paste. Whisk in the vanilla extract, then set aside to cool a little.

In another smallish bowl, combine the flour with the bicarbonate of soda and pinch of salt.