Preheat oven to 350°.
To prepare cheesecake, place 1/2 cup sugar, wafers, and dash salt in a food processor; process until mixture resembles sand. Place 1 egg white in a small bowl; stir with a whisk until frothy. With the processor on, add 2 tablespoons egg white through food chute, processing until blended (discard remaining egg white). Firmly press mixture into bottom and slightly up sides of an 8-inch springform pan coated with cooking spray. Bake at 350° for 10 minutes; cool completely on a wire rack.
Reduce oven to 300°.
Combine 1 1/2 cups sugar, 3 tablespoons cornstarch, and remaining dash salt in a large bowl. Add cheeses; beat with a mixer at medium-high speed until smooth. Reduce mixer speed to low. Add vanilla and 1 teaspoon juice; beat just until combined. Add eggs, 1 at a time, beating after each addition just until incorporated. Add remaining 2 egg whites; beat just until incorporated.
Pour cheese mixture into prepared pan. Bake at 300° for 1 hour and 15 minutes or until a 3-inch circle in the center of the cheesecake barely jiggles when the side of the pan is tapped. Turn oven off. Leave cheesecake in oven with the door open for 30 minutes. Remove cheesecake from oven; run a knife around outside edge. Cool to room temperature on a wire rack. Cover and chill at least 8 hours. Garnish cake with strawberries, if desired.
To prepare sauce, combine sliced strawberries, 1/2 cup water, and 2 tablespoons sugar in a small saucepan over medium-high heat; bring to a boil. Reduce heat, and simmer 5 minutes. Remove from heat. Strain mixture through a sieve into a bowl, pressing lightly with a spatula; discard solids. Return mixture to pan. Combine 1 tablespoon water and 2 teaspoons cornstarch in a small bowl, stirring with a whisk. Add cornstarch mixture to pan. Bring to a boil; cook 1 minute, stirring constantly. Transfer mixture to a bowl; cool to room temperature. Stir in 2 teaspoons juice.
If you make this cake in a nine-inch springform pan, cut the baking time by about 15 minutes. The center of the cake may appear looser than expected, but it will become firmer as it chills overnight.