Directions

1. Whisk egg whites in a large bowl until soft peaks form. Add salt and 1 tablespoon confectioners' sugar, and whisk until stiff peaks form. Using a rubber spatula, gently fold in vanilla and remaining 1/2 cup plus 3 tablespoons confectioners' sugar until incorporated. Fold in flour and butter until well combined.
2. Heat a pizzelle iron according to manufacturer's instructions. Coat with cooking spray, place 1 teaspoon batter on the iron, and close cover. Cook until steam subsides and wafer is golden brown, about 1 minute. Remove wafer with an offset spatula. Working quickly, place the wafer in a mini muffin tin and gently push down the center to form a cup. (The wafer will cool and harden almost immediately.) Repeat with remaining batter. Let cool completely. (Wafers can be stored in an airtight container for up to 2 days.)
3. Fill wafers with 1-inch scoops of ice cream or sorbet, and serve immediately.