In a food processor, combine the powdered sugar, almond flour, and graham crackers. Process until completely fine.
In a stand mixer fitted with a whisk attachment or using a handheld mixer, beat the egg whites until thickened. Add the granulated sugar and continue to beat until stiff peaks form.
Gently fold the beaten egg whites into the ground almond and graham cracker mixture until combined, but be careful not to overmix. It should be the consistency of “molten lava” but not runny, about 40-65 folds. Transfer the batter to a piping bag fitted with a 0.4 inch (10 mm) circular tip. On a parchment lined baking sheet, pipe 1 1/2 inch (4 cm) circles at least 2 inches apart. Repeat with remaining baking sheets.
Firmly tap the baking sheets against the counter to remove excess bubbles. Allow to rest uncovered 30-40 minutes to form a shell.
Preheat oven to 300˚F (150˚C).
Bake the macarons in preheated oven until the tops become firm, 15-20 minutes. Allow to cool before removing from baking sheet.