Makes about 30 cookies
1 1/4 cups whole blanched almonds
1 1/2 teaspoons cornstarch
1/2 cup confectioners' sugar
2 large egg whites
Pinch of kosher salt
1/3 cup plus 2 tablespoons granulated sugar
1/2 teaspoon almond extract
1 tablespoon amaretto
1/2 cup turbinado sugar, for sprinkling
Preheat oven to 300 degrees.
Place almonds, cornstarch, and confectioners' sugar in the bowl of a food processor; pulse until almonds are very finely chopped.
Place egg whites in the bowl of an electric mixer fitted with the whisk attachment. Add salt and beat on medium speed until foamy and light. Gradually add granulated sugar in a slow, steady steam and continue beating until stiff and glossy. Beat in almond extract and amaretto.
Using a rubber spatula, gently fold in ground almond mixture.
Drop heaping teaspoonfuls of batter onto parchment paper-lined baking sheets. Sprinkle each cookie generously with turbinado sugar.
Transfer to oven and bake until cookies are pale golden and begin to crack slightly, about 15 minutes. Reduce oven temperature to 200 degrees. Leave oven door ajar to release some of the heat. Let cookies stand in oven until completely dry and crisp, 25 to 30 minutes more.
Let cookies cool briefly on baking sheets, before transferring to a wire rack to cool completely. Store in an airtight container up to 3 days.