Combine crumbs, 3 teaspoons of Zsweet, and butter.
Pour into a 10 inch pie pan. Bake 10 minutes. Remove from oven. Set aside.
In medium bowl, with electric hand mixer, blend cream cheese and remaining Zsweet, at medium speed until well creamed. Add one egg at a time, mixing well after each. Blend in vanilla, whip on high, then stir in raspberries; pour into crust.
Bake at 325°F for 45 minutes
Cool, then spread sour cream over top of pie about 1/8" thick. Top with raspberries if desired.