If cooking in an oven preheat to 375°F (190°C).
Make the batter. In a small mixing bowl mix together the flour, sugar, baking powder, and salt.
Add the lemon zest, olive oil, and plant milk. Mix to form a smooth batter.
Divide the batter between 2 x 6oz (177ml) ramekins. If you will be baking them in an oven sit them on a baking tray. No need if using an air fryer.
Mix the liquid. Stir the cornstarch and lemon juice together in a small bowl, working out any lumps. Add the sugar and zest, then pour in the freshly boiled water. Mix well.
Pour the liquid gently over the top of the cake batter until it's about ⅛ an inch below the rim of the ramekin. It will look all wrong and might curdle a bit but don't worry. Magic will happen!
Bake in a preheated oven at 375°F (190°C) for 28 to 30 minutes, or at 325°F in an air fryer for about 18 to 19 minutes, until visibly risen, puffy, and starting to turn golden brown.
Important. Leave to rest for 10 minutes before digging in! The sauce needs a little time to thicken. Be careful, though, as it will still be REALLY hot!
