1 1/2 cups granulated sugar
5 large egg whites (see Cook's Note)
1/4 teaspoon kosher salt
1/2 teaspoon ground cinnamon
1/2 teaspoon vanilla extract
1 cup crushed chocolate sandwich cookies, such as Oreos (about 10 cookies)
I like separating the eggs one at a time into a separate small bowl first, in case I break a yolk. Even the tiniest bit of yolk will prevent whites from getting fluffy.