Follow these easy steps to create your delicious Southern-style baked mac and cheese:

1. Preheat the Oven: Preheat your oven to 350°F (175°C).
2. Cook the Pasta: Boil a large pot of salted water. Add the elbow macaroni and cook until al dente, about 6-8 minutes. Drain and set aside.
3. Make the Cheese Sauce: In a medium saucepan, melt the butter over medium heat. Stir in the flour and cook for 1-2 minutes to create a roux.
4. Add Milk: Gradually whisk in the milk, stirring continuously until the mixture thickens, about 5 minutes.
5. Incorporate the Cheese: Lower the heat and add the cheddar, mozzarella, and Parmesan cheeses. Stir until fully melted and smooth.
6. Season: Add the garlic powder, onion powder, mustard powder, salt, and pepper. Mix well to combine.
7. Combine Pasta and Cheese Sauce: In a large bowl, mix the cooked macaroni with the cheese sauce until fully coated.
8. Transfer to Baking Dish: Pour the mac and cheese mixture into a greased 9×13-inch baking dish.
9. Add Topping (Optional): If desired, mix breadcrumbs with melted butter and sprinkle evenly over the mac and cheese for added crunch.
10. Bake: Place in the preheated oven and bake for 20-30 minutes, or until bubbly and golden on top.
11. Cool: Remove from the oven and let sit for about 5 minutes before serving.

With these simple steps, you will have an incredible dish of Easy Southern Style Baked Mac and Cheese ready to enjoy!