Rub the sugar together with the lemon zest until it turns pale yellow and releases a strong lemon aroma.
Mix the flavored sugar with the butter and lard using a fork (it’s easier to mix by hand than with an electric mixer).
Add the flour and combine everything, pressing the dough with your hands until it comes together and forms a ball. If it feels too dry and crumbly, add a few drops of water.
Cover the dough and refrigerate for one hour.
Preheat the oven to 340°F (170°C).
Remove small pieces of dough and shape them into small balls, pressing them firmly together so they hold. They should be small, about 20–25 g each.
Line a baking sheet with parchment paper and place the cookies on it, spacing them about ¾ to 1 inch (2–3 cm) apart.
Bake for 10–15 minutes. The areias should be lightly golden and still soft; they will firm up as they cool.
While still warm, coat the cookies in sugar or in a mixture of sugar and a little cinnamon.