Bring a large pot of water to a boil; salt generously. Add broccoli rabe. Cook until leaves are wilted, about 1 minute. Using a slotted spoon, transfer broccoli rabe to colander; drain well.
Return water to a boil, and add pasta; cook until al dente, according to package instructions. Drain, reserving 1/2 cup cooking liquid.
Meanwhile, heat oil in large skillet over medium-low heat. Add garlic; cook, stirring, until soft, 30 seconds, being careful not to brown. Add anchovy fillets, if using, and crushed red pepper; cook, stirring, 1 to 2 minutes. Stir in broccoli rabe; cook until heated through, 3 to 4 minutes.
Add pasta to broccoli rabe mixture; toss to combine, adding reserved cooking water as desired. Season with 1/2 teaspoon salt and 1/8 teaspoon pepper. Serve with Parmesan and lemon wedges.
When choosing broccoli rabe, look for bright-green leaves and small florets with no yellow spots. The stalks are also edible; just trim the tough ends.