In a bowl, mix together the flour, yeast, a pinch of salt, the sugar, eggs, half the lard, the grated lemon rind and the liqueur. Mix until smooth. Then form a large role in a circle shape, and place on a baking sheet, well-greased with lard. Bake in an oven preheated to 180° C for 30-40 minutes.
In the meantime, beat the white of one egg and combine with the icing sugar. When the cake is cooked, turn off the oven and brush the surface of the cake with the egg white mixture. Decorate with the coloured sprinkles and leave in the cooled oven until the meringue has solidified slightly