Apple Empanadas With Almond Pastry Cream

Name: Apple Empanadas With Almond Pastry Cream
Ingredients: 1 large egg, beaten; 2 -3 tablespoons unsalted butter; 3 large Granny Smith apples, cored, peeled and cut into 1-inch dice; 1 dash turbinado sugar; 3 tablespoons brown sugar; 1 teaspoon ground cinnamon; 1 pinch salt; bench flour, for dusting; almond pastry cream, at room temperature, recipe follows; 1 (17 1/3 ounce) box frozen puff pastry, thawed according to package directions; 1 1/2 cups whole milk; 1/2 cup sugar; 2 tablespoons almond paste; 4 large egg yolks; 2 tablespoons cornstarch; 3 tablespoons unsalted butter