Preheat your oven to 450 F.
Place the cauliflower pieces on a large baking sheet, and toss with olive oil.
Add whole jalapenos to the baking sheet.
Season with salt and place in a single layer. Place the cauliflower in the oven on the middle rack and roast for about 20 minutes or until golden brown. Let cool.
When finished roasting, de-seed the jalapeno and remove stem, dice.
Meanwhile, melt the butter in a medium saucepan over medium-low heat.
Add diced jalapeno to the pan.
Add milk and cream and seasonings.
Stir over medium-low heat until the mixture starts to simmer and thickens.
Add cream cheese and stir to melt.
Turn off the heat and add the rest of the cheese, stir to melt.
Place roasted cauliflower into an 8x8" or equivalent greased baking dish.
Pour the cheese sauce over cauliflower. Add crumbled bacon, if using, and sprinkle with any additional cheese if you wish.
Bake for 15-20 minutes.
Optional: Broil for additional 2-3 minutes to brown the cheese.