Preheat the oven to 180°C.
In a large mixing bowl, beat together the lard and butter with a wooden spoon.
Slowly add the sugar, egg yolk and lemon peel, and set aside.
In a separate bowl, combine the cinnamon and flour, and gradually work into the butter mixture with your hands to make a smooth, manageable dough.
On a lightly floured work surface, roll the dough into a thick sausage and cut into discs.
Roll each disc into a sausage and curve into a half-moon shape. Place on a baking tray lined with baking paper, and bake until golden, about 8 – 10 minutes.
Place the icing sugar in a large mixing bowl. Once the cookies are baked, very gently place them in the icing sugar. Cover abundantly with the sugar and arrange on a serving dish.