Preheat the oven to 375°F (190°C).
Heat 1 tbsp olive oil or butter in a large skillet over medium heat.
Season 2 boneless, skinless chicken breasts with salt, pepper, and garlic powder. Cook for 5-7 minutes per side until fully cooked. Remove and chop into bite-sized pieces.
Steam or blanch 3 cups broccoli florets for 4-5 minutes. Drain well.
In a bowl, combine 8 oz softened cream cheese, 1/2 cup heavy cream, 1 cup shredded cheddar cheese, 1 tsp garlic powder, 1 tsp onion powder, salt, and pepper. Mix until smooth.
Combine chopped chicken, broccoli, and sauce in a large mixing bowl. Transfer to a greased 9x13 casserole dish and top with the remaining cheddar cheese.
Bake for 25-30 minutes until bubbly and golden on top.