Preheat the oven to 350 degrees. Prepare a 9x13 casserole dish with nonstick cooking spray.
Fill large stockpot with water to three-quarters full. Add about 1 teaspoon salt. Bring the water to a boil over high heat. Add the cauliflower florets and cook for 10 minutes or until fork tender. Drain the cauliflower well and place in the casserole dish.
Sprinkle half of the bacon over the cauliflower and tuck into the cauliflower florets
Meanwhile, in a large skillet, melt the butter over medium-low heat. When the butter is melted, add the heavy cream and bring to a boil, stirring often. Allow to simmer for 10 minutes. Stir in 2 ½ cups of the cheese and stir until melted. Allow sauce to simmer, stirring often, for an additional 3 to 4 minutes or until the sauce coats the back of a spoon and begins clinging to the sides of the skillet
Pour the sauce over the cauliflower and bacon. Top with the remaining cheese and bacon
Bake for 45 minutes or until the cheese has melted and the cauliflower begins to brown