Whisk 100 g soft butter and 100 g sugar together in a bowl until the mixture is light and creamy.
Add 1 pcs egg and 1 tsp vanilla sugar, and continue whisking.
Finely grate the lemon zest from 1 pcs organic lemon, and fold it into the dough.
Sift in 150 g plain flour and ½ tsp baking powder, and stir until the dough is smooth.
Shape the dough into 8 small balls, and press them lightly flat.
Place a piece of baking paper in the air fryer basket, and arrange the biscuits with a little space between them.
Bake the biscuits in the air fryer at 180°C for 8-10 minutes, until they are golden.Start the online kitchen timer here
Let the biscuits cool on a wire rack before serving.
Notes
Tips for the dough:
Use cold butter
This is a classic shortcrust pastry. To achieve the right crisp, "short" texture, it is essential to use ice-cold butter, cut into cubes. The butter should be worked quickly into the dry ingredients so that it does not get too warm.
Bring the dough together, do not knead it
When the dough is brought together with the egg, it should only just barely come together into a cohesive ball. It must absolutely not be kneaded. Kneading develops gluten, which will make your biscuits chewy and hard instead of tender and crisp.
The importance of chilling
It is essential to let the dough rest in the fridge as described. The cold temperature firms up the dough, which is necessary in order to roll and cut neat, even slices. It also helps the biscuits hold their shape better while baking in the hot air fryer.
Tips for flavour and decoration:
Organic lemon
Since you will be using the zest from the lemon, it is best to choose an organic, unwaxed lemon. The flavour of fresh lemon zest is far more aromatic and complex than that of synthetic flavourings. Grate only the outermost, yellow part of the peel, as the white layer is bitter.
The consistency of the icing
To make the perfect icing, add the lemon juice to the icing sugar very carefully – a few drops at a time. Stir thoroughly between each addition until you have a thick but still spreadable consistency. An icing that is too thin will turn transparent and run off the biscuits.
Variations:
Lemon and poppy seeds
Lemon and poppy seeds are a classic and delicious combination. Try adding a tablespoon of poppy seeds to the dough along with the dry ingredients for extra texture and a lightly nutty flavour.
Other citrus fruits
The recipe is easy to vary by swapping the lemon for other citrus fruits. Try, for example, making them with finely grated zest and juice from lime or orange for a completely different taste experience.
Air fryer-specific tips:
Plenty of space in the basket
Place the biscuits with plenty of space in the air fryer basket. They need room for the hot air to circulate effectively around each individual biscuit, ensuring even baking and maximum crispness.
Use baking paper
Place a piece of trimmed baking paper in the bottom. It prevents the dough from sticking in the ridges of the basket and makes it much easier to remove the finished biscuits. It also saves considerably on cleaning.
Keep an eye on the edges
Biscuits bake quickly in an air fryer, and the edges can turn dark in an instant. Check on them a minute or two before the stated baking time is up, especially the first batch, to get to know your own air fryer's precise performance.