Heat oven to 400ºF. Cut cauliflower into florets and toss with 1 tablespoon of olive oil. Place on a rimmed baking sheet and season with salt and pepper. Cut off the top of the head of the garlic and place on a sheet of foil. Drizzle with olive oil and wrap tightly. Place on baking sheet with cauliflower.

Roast for about 20 minutes, or until cauliflower is golden and tender. Continue roasting garlic an additional 5-10 minutes, or until caramelized and fragrant. Once garlic is cool, press out of skins and set aside.

Meanwhile, cook bacon in a large Dutch oven or pot over medium heat. Once crisp, remove to a paper towel lined plate. Let cool and crumble. Discard all but 1 tablespoon of bacon fat and return to heat. Add the onion, celery and carrot and cook, stirring occasionally, for about 10 minutes. Stir in the spices and flour and continue cooking for 2 minutes.

Whisk in the wine and water, making sure to scrape up any browned bits that may have formed on the bottom of the pot. Add the broth, bay leaf and garlic. Increase heat to high and bring to a boil, then reduce to medium-low and simmer for 10 minutes.

Add the cauliflower and continue cooking 5 minutes.

Remove the bay leaf. Working in batches, purée the soup in a blender until your desired consistency is reached. Add additional broth as needed. Return to pot and set over medium-low heat. Stir in half and half and parsley and cook until warmed through. Add salt and pepper to taste.

Serve with a drizzle of olive or white truffle oil, if desired, and top with the crumbled bacon.