Beat the room-temperature butter with the sugar using a mixer.
Add the eggs and beat, then pour in the lemon juice, add the zest and beat again.
Sift the flour with the baking powder and mix in. If you like, tint the dough with yellow food coloring or turmeric.
Knead the dough with your hands - it will be sticky - and refrigerate for 1 hour.
Roll the dough into balls the size of a walnut, coat them in powdered sugar and place on parchment paper.
Bake in a well-preheated 170-180°C oven until done, 20-30 minutes.