In a medium saucepan, combine 3/4 cup sugar, 3 tablespoons cornstarch and 1 1/3 cup cold water. Mix until smooth. Bring mixture to a boil, cook and stir for 2 minutes or until thickened. Remove from heat.
Stir in 1/4 cup raspberry gelatin powder until dissolved. Cool to room temperature. Refrigerate until slightly thickened.
In a small mixing bowl, combine one 8 ounce package of cream cheese, 1/4 cup powdered sugar, 2 teaspoons milk, and 1 teaspoon of vanilla.
Spread the filling into a graham cracker crust.
Next, spread the raspberries over the filling.
Spread the topping mixture over the top of the raspberries gently.
Chill until ready to serve, and top with whipped cream.