Mix the eggs and sugar together. Grate the tonka bean and the lemon zest with the zester blade and add to the mixture.
In a second bowl, mix the flour and baking powder.
Grate the cold butter with the extra coarse blade of the Elite Box Grater. Add it to the flour mixture and knead roughly and briskly.
Add the egg and sugar mixture and knead into a dough.
Divide the dough in two parts and leave to rest in the fridge for at least an hour. Overnight is fine as well.
Preheat oven at 180°C / 160°C (circulating air)
Bake in the preheated oven for approx. 8-10 minutes.
Optional: decorate with icing and stars after baking.