Preheat oven to 375°F. Grind crackers and sugar in processor until coarse crumbs form. Add butter and process until crumbs are evenly moistened. Press crumb mixture firmly onto bottom and up sides of 9-inch-diameter tart pan with removable bottom. Bake until crust is firm to touch, about 8 minutes. Cool crust on rack.
Filling and Topping:
Make Filling and Topping
Using electric mixer, beat cream cheese and sugar in medium bowl until smooth. Beat in sour cream, lemon juice and vanilla. Spread filling cooled crust. Chill until firm, at least 4 hours. (Can be made 1 day ahead. Cover; keep chilled.)
Arrange berries over filling, whisk jam in small bowl to loose consistency. Drizzle over berries. Serve immediately or chill up to 3 hours.
Yield: 8 servings.