Heat the oven to 150 degrees C (fan).
Line two baking trays with baking paper or silicone mats. Whisk the egg whites to stiff peaks, in a stand mixer with the balloon whisk attachment, or with an electric hand whisk.
Add the sugar, almonds and amaretto and fold together with a rubber spatula or spoon to form a stiff, sticky almond paste.
Sift the icing sugar into a bowl.
Dampen your hands, then take small pieces of the mixture and roll into balls approx 2-3 cm in size. Roll the balls in the icing sugar to coat fully, then place then on the lined baking trays, 2-3 cm apart. There is no need to flatten the balls.
Bake for 18-20 minutes until a pale golden colour with cracked tops.
Leave on the baking trays to cool completely.
* As an alternative to alcohol, use 2-3 drops vanilla extract.
These will keep well in an airtight tin for up to a week.
From Martha Collison's great new book 'Crave'.