1. Preheat oven to 400°.
2. Combine first 3 ingredients in a food processor; process until finely ground. With motor on, drizzle butter through food chute; process until blended. Press about 1/4 cup crumbs into the bottom and up sides of each of 8 (4-inch) tart pans coated with cooking spray. Bake at 400° for 10 minutes or until toasted. Cool.
3. Preheat broiler.
4. Spoon curd evenly into crusts. Place egg whites and salt in a large bowl; beat with a mixer at high speed until soft peaks form. Combine granulated sugar and 1/4 cup water in a saucepan; bring to a boil. Cook, without stirring, until a thermometer registers 250°. Pour hot syrup in a thin stream over egg whites, beating until stiff peaks form. Spread egg white mixture over tarts. Broil 30 seconds or until lightly browned.