Mix flour, salt and sugar. Add 2 ounces butter and carefully work together to form a rough dough ball. Add the water until the dough just comes together, about 2-3 minutes. Wrap in plastic and let rest about 15 minutes. Toss the apples, huckleberries and sugar together.
Place apples on dough.
Fold dough over fruit. Brush melted butter over edges. Bake in oven about 35-40 minutes until very dark and crispy. Slide the cooked tart on a rack to cool. Serve with ice cream.