Follow these step-by-step instructions to prepare a creamy, cheesy cauliflower bake:

1. Preheat the oven: Set your oven to 400°F (200°C) to ensure it’s ready for baking.
2. Prepare the cauliflower:
   • Toss the cauliflower florets with olive oil, 1/2 teaspoon of salt, and 1/4 teaspoon of black pepper.
   • Spread the florets evenly on a baking sheet and roast for 15-20 minutes, or until tender and lightly browned.
3. Make the cheese sauce:
   • In a medium saucepan over medium heat, melt the butter.
   • Stir in the flour, whisking continuously for about 1 minute until the mixture is smooth and bubbly.
   • Gradually whisk in the milk, ensuring there are no lumps.
   • Continue whisking for about 5-7 minutes until the sauce has thickened.
4. Add the cheeses and seasonings:
   • Lower the heat and add the cheddar, mozzarella, and Parmesan cheeses to the sauce.
   • Stir until the cheeses are fully melted and the sauce is smooth.
   • Mix in the garlic powder, onion powder, paprika, mustard powder, the remaining salt, and black pepper.
5. Combine cauliflower and cheese sauce:
   • Place the roasted cauliflower florets into a baking dish.
   • Pour the cheese sauce over the cauliflower, ensuring all pieces are well-coated.
6. Prepare the topping:
   • In a small bowl, mix the breadcrumbs with a tablespoon of olive oil or melted butter to moisten them.
   • Sprinkle the breadcrumb mixture evenly over the cheesy cauliflower.
7. Bake the dish:
   • Place the baking dish in the preheated oven and bake for 20-25 minutes, or until the top is golden brown and crispy.
8. Garnish and serve:
   • Remove from the oven, let it cool slightly, and garnish with chopped fresh parsley before serving.