Preheat the oven to 170°C and line a baking tray with paper.
Place eggs, sugar, and grated lemon rind into a mixing bowl. Beat with electric beaters until the mix looks pale and thick.
Sift in the flour and baking powder, then add the almonds. On a floured work surface, bring the dough together in a ball until smooth.
Split the mixture in half. Form 2 logs around 25cm long x 5cm wide and place on the baking tray, leaving some space in between. Bake for 20-25 minutes until the dough is firm to touch and golden on top. Remove from the oven and cool completely for an hour.
Preheat the oven to 140°C.
Now that the dough is cool, use a sharp knife to cut 0.5cm slices from each log on an angle.
Lay slices flat on the baking tray and place in the oven for 15-20 minutes, turning once, until completely dried out. Remove from oven and allow to cool completely again.
These keep well, stored in an airtight container for 2-3 weeks.