Step 1

Preheat the oven to 170C/325F. Line two baking trays with a silicone mat or baking parchment.

Step 2

Using a hand whisk or mixer, whisk the egg whites to stiff peaks.

Step 3

Fold in the ground almonds, caster sugar and vanilla extract.

Step 4

Slowly stir in the amaretto. Add just enough so that the mixture is a thick paste that can be formed into a ball in your hand (it should be very sticky though).

Step 5

Place the caster sugar and icing sugar for rolling on two separate plates. Using a teaspoon, scoop out a chunk of the cookie mixture and roll it into a ball in your hands (about the size of a walnut - note, it will be sticky). Roll it in the caster sugar, then roll it in the icing sugar and place on the baking tray.

Step 6

Repeat with the remaining dough until you've used it all up. Leave a bit of space between the cookie balls as they will expand slightly during cooking.

Step 7

Use your finger to squash the cookie balls a little (they will crack a little at the edges - that's fine).

Step 8

Then place in the oven to cook for 15 minutes.

Step 9

Take out of the oven, leave to cool for 5 minutes then remove from the baking tray. You can serve them warm, or allow them to cool completely on a cooling rack.