Preheat your oven to 425°F (220°C) and grease a 9x13 inch baking dish.

In a large bowl, toss the broccoli florets with olive oil, salt, and pepper. Spread them on a baking sheet and roast for 14-16 minutes.

Lower the oven temperature to 375°F (190°C).

In a saucepan over medium heat, melt the unsalted butter, whisk in the flour to make a roux, gradually add warm milk and cook until thickened.

Stir in garlic powder, cayenne pepper, and salt and pepper. Add shredded cheddar cheese until melted.

Crush the Ritz crackers in a bag, combine with melted butter until coated.

Spread roasted broccoli in the baking dish, pour cheese sauce over then sprinkle the cracker mixture on top.

Bake at 375°F (190°C) for 16-20 minutes until bubbly and golden brown.

Let cool for 15 minutes before serving.