Preheat your oven to 375°F (190°C).
Place the cauliflower florets in a large pot of salted boiling water. Cook for about 5-7 minutes, until the cauliflower is tender but still a bit firm.
Drain the cauliflower and pat it dry with paper towels. Transfer to a large bowl.
Drizzle the olive oil over the cauliflower and season with salt and pepper. Toss to coat evenly.
Add the shredded cheddar cheese, Parmesan cheese, sour cream, heavy cream, minced garlic, onion powder, and dried thyme to the bowl. Mix everything together until well combined.
Transfer the mixture to a greased 9×13 inch baking dish and spread it out evenly.
Bake in the preheated oven for 25-30 minutes, until the top is golden brown and bubbly.
Garnish with chopped fresh parsley before serving.
Variations & Tips
For a fun twist, you can add some cooked crumbled bacon or diced ham to the casserole for extra flavor and protein. If you have family members who aren’t big cheese fans, reduce the cheddar and Parmesan and add a bit more sour cream for a creamier texture. Some kids love a little bit of crunch, so topping with a handful of crushed pork rinds can be a hit. And for an extra boost of veggies, feel free to mix in some broccoli or spinach.
