Beat the egg whites until stiff peaks form, using an electric hand mixer.
In a food processor, finely chop the mulberries, dates, linseeds and sweetener until they resemble the consistency of brown sugar. Mix with ground almonds.
Add the dry ingredients to the egg whites and mix gently using a metal spoon, in a figure of 8 manner, until just combined. Do not over-mix.
Add amaretto for the mixture to form into a paste.
Bake for 15 minutes. Do not overcook as the Pastini will keep cooking and hardening as they cool.