Process all ingredients in a food processor until mixture is pebbly and has begun to stick together. Wrap in plastic wrap and chill for about an hour. Then roll out dough (the easiest is between two sheets of wax paper as it is sticky when warm, using more flour to make sure it doesn't stick) and lay it in a 9" tart pan (with sides approximately 3" tall), ideally one with a removable bottom, and lined with parchment paper. Trim edges, doubling over and tidying as necessary. Pre-bake tart shell for about ten minutes at 375ºF.  Do not permit to over-brown as the crust will be baked additionally with the topping.

Cream the room-temperature cream cheese and goat cheese with the sugar, egg, egg white, and vanilla extract until smooth.  Pour it into the baked crust and bake for fifteen minutes at 350 - this will not be fully baked, but sufficient to keep the cheese layer separate from the Concord grape layer.  NOTE:  You can have a "skinny" cheese layer, pictured above, by reducing ingredients by half.

CONCORD GRAPE LAYER (Ingredients 11-17)
Beat eggs until light-colored. Gradually beat in the sugar and beat until the mixture is creamy and slightly thickened. Add the jar of filling and water, beating until thoroughly mixed.  Pour onto the partially-cooked cheese layer.   Bake approximately 30 minutes at 350ºF. Filling will rise as it cooks, so do not overfill.

BLUEBERRIES
Once tart has completely cooled, arrange fresh or frozen blueberries on top, pressing lightly into the cooked filling.  May coat the berries lightly with apricot jam (heated and thinned if necessary with liqueur).

Chill the cheesecake thoroughly before cutting - and then serve, and decorate the plate with extra berries if you like.