For the lemon tart, knead a dough from 50 g sugar, 100 g butter and 150 g flour, 1 egg and 1 pinch of salt, place in the buttered tart pan, prick several times with a fork. Bake for about 30 minutes (at 160 °C).
For the lemon mixture, mix 100 g sugar, 2 eggs and 1 egg yolk in a saucepan and heat. Add the lemon juice, zest and limoncello, remove from heat. Separately, leave out the 50 g of butter, add it to the lemon mixture and mix everything well. Heat again if necessary, the mixture must become thick!
Spread on the baked base and bake for another 30 minutes at 160 °C. The lemon tart should get an orange-golden brown color.