Preheat the Oven: Begin by preheating your oven to 425°F (220°C). This is crucial for achieving that crispy, golden crust.
Prepare the Filling: In a large mixing bowl, combine 2 cups of cooked, shredded chicken with 1 cup of Alfredo sauce, 1 cup of shredded mozzarella cheese, 1/2 cup of grated Parmesan cheese, 1 teaspoon of garlic powder, 1 teaspoon of Italian seasoning, and salt and pepper to taste. Mix until everything is well-incorporated.
Roll Out the Dough: On a lightly floured surface, roll out your pre-made pizza dough into a large circle, about 12 inches in diameter. Cut this circle in half to create two semicircles.
Fill the Dough: Take one half of the dough and spoon a generous portion of the chicken Alfredo mixture onto one side, leaving about an inch of space from the edge. Be sure not to overfill!
Seal the Calzone: Fold the other half of the dough over the filling to create a pocket, and press the edges together to seal. Use a fork to crimp the edges for an extra secure seal.
Apply Egg Wash: Transfer the calzones to a baking sheet lined with parchment paper. Brush the beaten egg over the top of each calzone to promote browning in the oven.
Bake: Place the baking sheet in the preheated oven and bake for 15-20 minutes, or until the calzones are golden brown.
Cool and Serve: Once baked, allow the calzones to cool for a few minutes before slicing. This will make them easier to handle and keep the filling intact.