If your air-fryer has a preheat function, set it to 160C. Butter the base and sides of an 8-inch springform cake tin and line the base with baking parchment. Tip the butter, sugar, lemon zest, vanilla and a pinch of salt into a bowl and beat using an electric whisk. Whisk for 4-5 mins or until pale and fluffy.

With the beaters running, pour in the beaten eggs, a little at a time, whisking well after each addition. If the mixture looks a little curdled, beat in 1 tbsp of the flour. Once the eggs have been used up, sift over the flour and baking powder, then gently fold to combine.

Pour the mixture into the cake tin, smooth out the top using the back of a spoon or palette knife, then put in the air-fryer for 30-45 mins or until golden, risen and a skewer inserted into the centre comes out clean. (The time will vary depending on the make and model of your air-fryer.)

Leave to cool in the tin for 10 mins, then remove and leave to cool completely on a wire rack. Slice carefully across the middle into two sponges.

For the filling, whisk the cream and honey to soft peaks. Crush in most of the blackberries, leaving a few whole. Pile the cream on top of one of the sponges, then sandwich the other sponge on top and dust with icing sugar. Best served on the day, but will keep for two days in the fridge.