For the breadcrumbs, heat the EVOO and butter over medium heat, melting the butter into the EVOO. Add the garlic and stir for 1-2 minutes. Add the breadcrumbs and stir until very fragrant and deeply golden in color. Remove the breadcrumbs from the heat and cool; toss with the parsley and cheese.
For the sauce, heat the EVOO, a couple of turns of the pan, over medium-high heat in a Dutch oven. Add the pancetta, guanciale or bacon and stir until rendered and crispy, 3-4 minutes. Add the onion, garlic, rosemary, thyme, red pepper flakes and raisins; stir to soften, 3-5 minutes. Add the white wine and stock, then set the cauliflower into pot; season with salt and pepper and cover. Cook for 15-20 minutes until very tender, then mash up the cauliflower into small pieces with a wooden spoon or potato masher.
Meanwhile, bring a large pot of water to boil for the pasta. Salt the water and cook the pasta to al dente. Add a cup of starchy cooking water from the pasta to the sauce just before draining.
Along with the starchy cooking water, stir the butter into the cauliflower sauce. Combine with the pasta and adjust the seasoning.
Serve in shallow bowls topped with garlic breadcrumbs.