PREHEAT oven 350°F.
SPREAD almonds evenly on a rimmed baking sheet.
BAKE almonds 4-5 minutes or until fragrant and golden brown WHILE STIRRING occasionally.
ALLOW almonds to cool slightly.
REDUCE oven to 225°F.
POSITION racks in center and top third of oven.
LINE two baking sheets with parchment paper.
PLACE 1/3 cup toasted almonds into a food processor (RESERVE remaining toasted almonds for garnish).
PROCESS almonds in food processor until finely ground.
ADD confectioners' sugar.
PROCESS almond mixture again until ground to a fine powder.
SET ASIDE ground almond mixture.
PLACE egg whites into bowl of an electric mixer.
ADD cream of tartar.
BEAT egg white mixture on low speed until egg whites are foamy.
ADD almond extract.
INCREASE speed to high AND BEAT until egg whites form soft peaks.
ADD 1 tablespoon granulated sugar WHILE BEATING.
CONTINUE ADDING remaining granulated sugar 1 tablespoon at a time WHILE BEATING.
BEAT until egg whites are shiny and firm.
FOLD ground almond mixture into egg whites just until incorporated. Do not over mix.
DROP 4 mounds of meringue batter onto each baking sheet, spacing them about 2 inches apart.
USE the back of a large wet spoon to SPREAD each mound into a 3-inch circle.
USE the back of a large wet spoon to FORM an indentation in the center of each circle.
BAKE meringues 2 to 2 ½ hours or until crisp and pale beige.
OPTIONAL: For extra-crisp meringues turn off oven, prop door ajar with a wooden spoon, and allow meringues to stand in oven overnight.
ALLOW meringues to cool for 10 minutes on pans.
PEEL meringues carefully from paper.
NOTE: Meringues can be made 3 days ahead and stored in an airtight container at room temperature.