Cut cauliflower into individual florets. Toss with 1 tablespoon olive oil. Transfer to a foil lined baking sheet. Sprinkle lightly with salt and pepper.
Cut the top off of the head of garlic. Drizzle with olive oil and wrap with foil. Place wrapped garlic on the baking sheet. Roast the cauliflower and garlic at 400 degrees F for 15-20 minutes. When the cauliflower is tender and golden remove from the oven.
The garlic will need to roast for a total of about 25-30 minutes. You can remove it to check it’s progress as needed - it should smell fragrant but not raw, be golden and tender.
Meanwhile, heat the butter in a cast iron dutch oven or medium-large stock pot. Add the onion, celery, and carrot. Saute over medium heat for about 10 minutes. Whisk in the salt, pepper, paprika, thyme, and flour and continue to cook for 2 more minutes.
Add the wine and water, whisking to combine with the flour mixture. Then, slowly add in the 2 cups broth. Add the bay leave and roasted garlic cloves. Bring mixture to a boil, then reduce heat to medium-low and simmer for 10 minutes. Add the cauliflower and simmer an additional 5 minutes.
Remove the bay leaf. Working in batches, add the soup to a blender or food processor and blend until pureed and smooth. Add additional broth during or after blending to achieve desired consistency. After all the batches have been completed, return to the pot. Stir in the half and half and parsley. Cook until just heated through. Adjust salt and pepper for tastes.
Serve immediately, topped with bacon and a drizzle of olive or truffle oil and a side of bread for dipping.