1. Steam the broccoli rabe until just tender, about 3 minutes. Coarsely chop.
2. Heat the olive oil in a large skillet. Add the garlic and cook over low heat until golden, about 3 minutes. Add the anchovies and crushed red pepper and cook for 1 minute. Add the broccoli rabe and cook, stirring, until the flavors are well blended, about 4 minutes. Season with salt and black pepper and keep warm.
3. Cook the fusilli in a large pot of boiling salted water, stirring occasionally, until al dente. Reserve 3 tablespoons of the pasta cooking liquid. Drain the fusilli and return it to the pot. Add the butter and toss well, then add the broccoli rabe and reserved liquid and toss again. Season with salt and black pepper and transfer to a warmed bowl. Serve at once, passing the cheese separately.