Heat a deep skillet or Dutch oven with the EVOO, 2 turns of the pan, over medium-high heat. Add the guanciale and brown until lightly crisp. Add the garlic, bell pepper, cubanelles, onions and fresno peppers, and cook until tender, 7 to 8 minutes. Add the pickled peppers and a big splash of their juice, about 2 tablespoons, and deglaze the pan - hold your head back or you'll really clean out your sinuses. Add the tomatoes and crush up a bit, then stir in the passata and basil. Simmer to thicken 30 minutes or so. Add the parsley, season with salt and pepper. Cool and store for a make-ahead meal. Reheat over medium flame.
To serve: While the sauce heats, bring a large pot of water to a boil. Salt the water and cook the pasta to al dente. Reserve a ladle of the starchy cooking water and drain. Toss the pasta with the butter and half the sauce. Add a little starchy water if too thick. Serve the pasta in shallow bowls, topped with the remaining sauce and pecorino cheese.