Preheat oven to 425. Line a rimmed baking sheet with parchment paper.
In a bowl, toss cauliflower with olive oil, smoked paprika, red pepper flakes, and salt. Spread florets evenly out on baking sheet. Roast in oven until tender and slightly blackened, about 20 minutes. Let cool for 5 minutes.
Combine all ingredients in a blender, and puree, adding additional water if necessary, until smooth and creamy.