Preheat your oven to 375°F and bring a large pot of salted water to a rolling boil. Cook elbow pasta until just shy of al dente, around 8-9 minutes, then drain and set aside without rinsing.
In a large Dutch oven or heavy-bottomed pot, melt butter over medium heat, then whisk in flour to create a roux. Cook this mixture for 1-2 minutes, stirring constantly, until it smells nutty and toasty but never browns.
Slowly pour in whole milk while whisking continuously to prevent lumps from forming in your sauce base. Continue cooking for 5-7 minutes until the mixture thickens enough to coat the back of a spoon.
Remove the pot from heat and stir in shredded cheeses, salt, pepper, cayenne pepper, garlic powder, and dry mustard until completely melted and smooth. This easy mac cheese combination creates incredible depth that simple recipes completely miss.
Add beaten eggs to the cheese sauce while stirring quickly to temper them, preventing scrambling in the final bake. Gently fold in cooked pasta, making sure every piece gets coated with that luxurious sauce throughout.
Transfer the entire baked mac and cheese family summer recipe mixture to a greased 9x13 baking dish, spreading evenly. Mix panko breadcrumbs with melted butter and fresh parsley, then sprinkle generously across the top layer.
Bake uncovered for 30-35 minutes until the breadcrumb topping turns golden-brown and the sauce bubbles gently around the edges. Let it rest for 5 minutes before serving to allow the texture to set properly.