Wash the lemon with hot water, dry it, finely grate the peel, squeeze out the juice. Heat the lemon juice with the water. Melt the butter in a saucepan or in the microwave, mix with the lemon water. Stir the chia seeds and cane sugar into the hot liquid, leave to soak for about 10 minutes.
In the meantime, mix the wholemeal flour with the vanilla sugar, salt, baking powder, cardamom and the lemon peel. Now add the liquid mixture and stir quickly with a tablespoon.
Line a baking sheet with parchment paper. Then use the spoon to place 22 piles of dough with a little space between them. Then press them flat into round talers.
Bake the biscuits without preheating at 180 ° C top / bottom heat for about 20 minutes until golden brown.
The cooled cookies stay nice and crispy in a tin can.