2 cups heavy cream
1 1/2 sticks unsalted butter
Preheat the oven to 325°. In a large pot of boiling salted water, cook the cauliflower florets until tender, about 7 minutes. Drain well. Spread the cauliflower on a large rimmed baking sheet. Bake for about 5 minutes, to dry it out.
In a small saucepan, combine the heavy cream with the butter and bring to a simmer over moderate heat just until the butter is melted.
Working in batches, puree the cauliflower in a blender with the warm cream mixture; transfer the puree to a medium microwave-safe bowl. Season with salt and cayenne. Just before serving, reheat the puree in the microwave in 1-minute intervals, stirring occasionally.