Prepare one large baking sheet by covering it with parchment paper.

Sift the flours and sugar into a large bowl.

Using a stand or hand mixer, whisk the egg whites with the salt until soft peaks form. Whisk in the almond extract (or liqueur) just until combined.

Transfer the whites into the dry ingredients and mix with your hands until a sticky dough forms.

Preheat your oven to 300F degrees.

Roll the dough into 1-inch balls, roll into the powdered sugar and place on the prepared baking sheets, 1 inch apart. Flatten the cookies slightly, then let them stand at room temperature for 15 minutes, while your oven is preheating.

Bake the amaretti cookies until the tops are cracked and the cookies are golden brown, about 20 minutes. Remove from oven and let them cool on the baking sheet for a couple of minutes, then transfer to a wire rack so they can cool completely.

The cookies will keep for up to 3 days in an airtight container.