Preheat the oven to 175ºC with heat up and down and prepare two or three trays with non-stick baking paper. Beat with manual rods in a wide container the eggs with the fine zest of half a washed lemon, the oil, a teaspoon of lemon juice or liquor, and the sugar.
Once the sugar is dissolved add the sifted flour with 3/4 teaspoon of chemical yeast and a good pinch of salt. Mix everything until you get a moist dough but it detaches from the walls of the bowl. If it is unmanageable, refrigerate for 30 minutes or add a little more flour -be careful not to overdo it-.
Grease a clean surface with oil and have more on hand to grease your hands to work the dough. Take small balls of dough -about the size of a walnut-, stretch forming strips about 10 cm long and join the ends forming donuts. Distribute in the trays, leaving a little separation between them.
To bake one tray at a time until lightly toasted, about 20 minutes. Wait a bit out of the oven before transferring to a wire rack.
For the icing, mix a few drops of lemon juice with plenty of sifted icing sugar and paint them when they are cold. Allow to dry before storing in an airtight container.