Grind the almonds (or use store bought ground almonds)
Heat the oven to 175°C (350°F)
Line a baking tray with parchment paper
Take a big bowl and a hand mixer and whisk the egg whites to stiff peaks
Fold in the almonds, sugar, vanilla powder and liquor and mix until you have an even paste
Use two separate plates, one for the sugar and one the powdered sugar.
Start forming small balls (~3 cm) then roll each first in sugar, then in the powdered sugar.
Place on the tray with a little space between each (they expand slightly in the oven but not much)
Squash each cookie just a little then bake in the oven for 15 minutes.