Preheat Oven: Preheat your oven to 325°F. Line 2 baking sheets with parchment paper.
Combine Dry Ingredients: In a large bowl add the almond flour, 1 cup of sugar and lemon zest. Whisk well.
Combine Wet Ingredients: To the bowl of your mixer add the egg whites and beat to a soft peak. Whisk in the almond extract.
Fold Together: Gently fold in the egg whites into the dry ingredients until the dough is moist.
Form Cookies: Use a small cookie scoop to scoop out equal amounts of dough, then roll into balls with slightly damp hands. Roll through the remaining ¼ cup of sugar. Place cookies on prepared baking sheets.
Bake and Cool: Transfer the baking sheets to the oven and bake for 25 minutes or until the cookies start to slightly turn golden and bottom is golden brown. Cool completely on cooling racks.
The rolled mixture should be sticky but fairly firm, and should hold their shape when placed on the baking tray.
The cookies will expand slightly in the oven and crack, so make sure they have ample room. They should also flatten out a bit as well.
These cookies can be stored in an airtight container, sealed jar or sealable bag at room temperature. They will last for at least 1 week.
Cool the amaretti cookies completely, then freeze in a single layer on a baking sheet. Once they're frozen, you can transfer them to a bag or an airtight container. The cookies will keep for up to 6 months.