Pastry:
5 tablespoons cold vegetable shortening (Crisco) in about 10 pieces
4 tablespoons cold unsalted butter, cut into 1/4” pieces
1 1/2 cups all-purpose flour
1/2 teaspoon (scant) salt
1/3 cup ice cold water
Peach Filling:
5 cups peeled and sliced fresh peaches (or peaches and nectarines; see note below)
1/3 cup sugar
2 1/2 tablespoons cornstarch
2 teaspoons lemon juice
1/2 teaspoon finely grated lemon zest (optional)
Heath Bar Crumb Topping:
1 cup coarsely chopped Heath bars (about three 1.4 ounce bars)
2/3 cup all-purpose flour
1/2 cup pecan halves or pieces
1/4 cup sugar
1/4 teaspoon salt
5 tablespoons cold unsalted butter, cut into 1/4” pieces