Step 1

Preheat the oven to 375°F. Grease a 13x9-inch casserole dish.

Step 2

In a medium saucepan set over medium-high heat, melt the butter. Whisk in flour for 1 minute until golden.

Step 3

Gradually whisk in the half-and-half until the sauce is smooth and thickened. Stir in the cream cheese and Parmesan until melted and incorporated. Stir in the garlic powder, salt, and pepper, then remove from heat.

Step 4

Combine the pasta, broccoli, chicken, and sauce in a large bowl and stir to combine. Transfer mixture to prepared baking dish. Sprinkle with mozzarella.

Step 5

Bake for 15 minutes, then broil for 2-3 minutes on high until the cheese is bubbly and browned. Serve warm.