Melt the butter and golden syrup in a pan over a low heat or in a microwave on high (800W).,

Finely grate the lemon zest into a large bowl and add the remaining ingredients.,

Pour the melted butter mixture into the bowl and stir to combine until it comes together, then mix in 1 tablespoon of water.,

Divide the mixture into three, then roll each piece into 5 even-sized balls – you should get 15 in total.,

Use the palm of your hand to squash the balls slightly (you can freeze them at this stage, ready to bake another day if you like).,

Transfer to the air-fryer, making sure there’s a 1cm gap in between them – you might need to do this in batches.,

Cook at 175°C for 15 minutes, then carefully remove the air-fryer basket or shelf and leave to cool for 5 minutes.,

Transfer the cookies to a wire rack to cool, while you crack on with the second batch.