Prep the oven and pan: Preheat oven to 375°F (190°C). Grease a 9x13-inch baking dish or similar casserole dish.
Par-cook the broccoli: Bring a large pot of salted water to a boil.
Add broccoli florets and cook for 2–3 minutes until bright green and slightly tender. Drain well and pat dry with paper towels to remove excess moisture.
Start the sauce: In a large skillet over medium heat, melt the butter. Add minced garlic and cook for 30 seconds until fragrant.
Make it creamy: Reduce heat to low.
Whisk in cream cheese until smooth and melty, about 1–2 minutes.
Add liquid and season: Slowly pour in the heavy cream, whisking until the sauce is silky. Stir in Dijon, onion powder, smoked paprika, salt, and pepper.
Stir in cheeses: Add 1½ cups shredded cheddar and the Parmesan. Stir until fully melted and the sauce is thick and glossy.
Taste and adjust seasoning.
Combine with broccoli: Add the drained broccoli to the skillet and fold to coat every floret with the cheese sauce. If your skillet is small, mix in a large bowl.
Assemble the casserole: Transfer the mixture to the prepared baking dish. Top with the remaining 1/2 cup cheddar.
If using, sprinkle crushed pork rinds or almond flour over the top for crunch. Add bacon now if desired.
Bake: Bake for 18–22 minutes, until the casserole is bubbling around the edges and the top is golden.
Rest and serve: Let it sit for 5–10 minutes to set slightly. Garnish with black pepper or chopped parsley and serve warm.