Crust: Preheat oven to 350 degrees. In a medium bowl, mix cracker crumbs, syrup and extract until crumbs are moistened. Pour into oiled 9-inch pie plate; press mixture evenly to form crust. Bake 5 minutes. Let cool while preparing filling.
Filling: Blend all ingredients in food processor or blender until smooth, about 30 seconds. Pour mixture into crust. Bake until top of pie is slightly browned, about 30 minutes. Cool and refrigerate until thoroughly chilled and firm, about two hours.
Alternatively, use a prepared graham cracker crust. For a no-bake cheesecake, omit cornstarch mixture. Pour filling into crust and refrigerate until firm, at least two hours or overnight. The texture will resemble that of a cream pie.
Feel free to experiment. Try adding vanilla-flavored liqueur instead of lemon juice and zest for a vanilla cheesecake. Or reduce the sweetener, eliminate the lemon juice and zest, and add pureed strawberries or raspberries to taste. Or add 12 ounces of melted semisweet chocolate instead of fruit. Or forget the crust and pour the filling into custard cups, chill and serve vegan pudding.