1	cup (96 g) graham cracker crumbs

2	tablespoons margarine, melted

3	large eggs, separated

1	large egg white

1/4	teaspoon cream of tartar

3/4	cup (15 g) + 2 tablespoons spoon-for-spoon sugar substitute such as Splenda 2 tablespoons cornstarch

4	cups (1 l) yogurt cheese made from nonfat plain yogurt*

1 1/2

teaspoons grated lemon zest

2	teaspoons pure vanilla extract

2	tablespoons sugar-free red raspberry preserves

1	cup (246 g) fresh raspberries, rinsed and drained dry

1. Preheat oven to 325°°F (160°C, Gas Mark 3).
2. Combine the graham cracker crumbs and margarine. Pat evenly over the bottom and about 1/2 inch (1.25 cm) up the sides of a 9 1/2-inch (23.75 cm) springform pan. Bake in oven for 15 minutes.
3. Meanwhile, using an electric mixer on high speed, beat the 4 egg whites and cream of tartar in a large bowl until foamy. Gradually add 6 tablespoons of the sugar substitute, 1 tablespoon at a time, beating until egg whites form stiff peaks.
4. In another large bowl, stir the remaining sugar substitute with the cornstarch, then add the egg yolks, yogurt cheese, lemon zest, and vanilla. Beat (using the unwashed mixer beaters) until well blended.
5. Fold beaten egg whites into cheese mixture. Spoon the mixture into the partially-baked crust. Bake in the oven until center barely jiggles when cheesecake is gently shaken, 50 to 60 minutes. Remove from oven and cool, then cover and chill for up to 1 day.
6. Melt preserves in a small pan over medium heat, stirring often. Cool, stirring occasionally, until the preserves form a thick syrup, about 5 minutes. Remove pan rim. Mound fresh raspberries on the cheesecake and drizzle with preserve syrup. Chill.
7. When ready to serve, cut the cheesecake into wedges. Sliding a pie server under each wedge, lift out gently onto individual dessert plates.