Apple and Cherry Pie

Ingredients

• 6 Granny Smith Washington apples, peeled, cored, and cut into 1/2-inch slices
• 3/4 cup granulated sugar
• 3 tablespoons all-purpose flour
• 1 1/2 tablespoons freshly squeezed lemon juice
• 1/2 teaspoon ground cinnamon
• Double-crust pie dough, purchased or homemade
• 2 cups pitted Bing cherries
• 2 tablespoons unsalted butter, cut into small pieces
• 1 egg
• 1 tablespoon water
• 2 tablespoons turbinado sugar or granulated sugar, for topping
• Whipped cream, for serving (optional)