In a bowl, mix the butter, sugar and lemon zest until creamy.
Add the egg and mix again.
Then add the lemon juice and continue to mix.
Add the flour, baking powder and mix with a spatula.
Wrap the dough in food foil and put it in the refrigerator for 30 minutes.
Break off a small amount of dough, form a ball-shaped flatbread (about the size of a walnut) in your palms, roll it in sugar, then in powdered sugar and place in the oven for 5 minutes at 180°C, then for another 10 minutes at 150°C.
Let the cookies cool on the tray before serving.
They turned out so crispy and the sweet and sour flavor is perfect for summer!
