Prepare the Broccoli: Preheat your oven to 375°F (190°C). Steam or blanch the broccoli florets for 3-4 minutes, until they are tender-crisp. Drain well and set aside.

Make the Cheese Mixture: In a large mixing bowl, combine the cream cheese, sour cream, cheddar cheese, Parmesan cheese, minced garlic, Italian seasoning, salt, and pepper. Mix until smooth and evenly combined.

Assemble the Casserole: Add the steamed broccoli florets to the cheese mixture and toss until the broccoli is well-coated. Transfer the mixture to a greased 9x9-inch baking dish, spreading it evenly.

Bake: Place the dish in the preheated oven and bake for 20-25 minutes, or until the casserole is bubbling and the top is golden brown.

Garnish and Serve: Remove the casserole from the oven and let it cool for 5 minutes. Garnish with crushed red pepper flakes for a hint of spice, if desired. Serve warm as a side dish or a main course.