In small bowl or glass measuring cup mix water with vinegar and dark brown sugar until sugar is dissolved. Place in freezer while readying other ingredients.

In bowl of food processor mix flour with salt. Cut butter into half inch pieces.

Add butter to flour and salt and process until it resembles small peas. Add chilled water mixture in a slow stream until dough comes together. Remove and cut into 2 pieces and wrap in plastic and refrigerate for at least 2 hours or up to 48 hours.

Roll out dough on a sheet of parchment paper and place onto rimmed sheet pan.

Mix all berries together and sprinkle on the 3 tablespoons sugar, cornstarch and lemon zest. Mix gently.

Pile berries in center of dough and leave a 2 inch border. Pull up dough all around and pleat gently.

Preheat oven to 425. Brush cream generously all around the dough and sprinkle the sugar around the crust.

Bake at 425 for 5 minutes. Turn oven down to 375 and cook for approximately 35-45 minutes. Look for a nicely browned crust.