Preheat your oven to 350°F (175°C) and prepare an 8x8-inch baking dish by spraying it with nonstick cooking spray.

Place the chicken in a bowl and season with garlic powder, onion powder, salt, and pepper.

Heat a large skillet over medium heat and add olive oil. Once hot, add the chicken and cook until browned and cooked through, about 6-8 minutes. Remove the chicken and set it aside on a plate.

Bring a pot of water to a boil. Blanch the broccoli florets for about 2-3 minutes, then drain and set aside.

In a large mixing bowl, combine the broccoli cheddar soup, sour cream, milk, lemon juice, the cooked chicken, broccoli florets, and 1 1/2 cups of shredded cheddar cheese. Mix everything together until well combined.

Transfer the mixture into the prepared baking dish, spreading it out evenly.

In a small bowl, mix the crushed Ritz crackers with the melted butter until coated. Sprinkle the cracker mixture over the top of the casserole, followed by the remaining 1/2 cup of shredded cheddar cheese.

Bake uncovered in the preheated oven for 30 minutes, or until the topping is golden brown and the casserole is bubbly. Allow it to cool for 5 minutes before serving. Enjoy!