Preheat oven to 375°. On a lightly floured surface, roll dough to a 1/8-in.-thick circle; transfer to a 9-in. pie plate. Trim crust to 1/2 in. beyond rim of plate; flute edge. , In a saucepan, combine the brown sugar, cornstarch, cinnamon and salt. Stir in water until smooth. Add the butter; bring to a boil. Add apples. Cook and stir for 4 minutes. , Add apple mixture to crust. In a bowl, whisk the pumpkin, milk, sugar, egg, cinnamon and salt until smooth; pour over apple layer. If desired, decorate edge with crust leaves., Bake until a knife inserted in the center comes out clean, 50-55 minutes. If necessary, cover edges with foil during the last 15 minutes of baking time to prevent overbrowning. Cool completely. If desired, serve with whipped cream or ice cream. Store in the refrigerator.