01 - Bring a large pot of generously salted water to a rolling boil. Add the mafaldine pasta and cook according to package directions. When 5 minutes of cooking time remain, add the broccoli florets to the pot. Cook until the pasta is al dente and the broccoli is tender-crisp. Reserve ⅓ cup of pasta cooking water, then drain through a colander.
02 - While the pasta cooks, warm the olive oil in a large skillet over medium heat. Add the minced garlic and sauté for about 1 minute until fragrant, taking care not to let it brown.
03 - Pour the heavy cream into the skillet and bring to a gentle simmer. Stir in the lemon zest, lemon juice, and Parmesan cheese. Season with salt and freshly ground black pepper. Stir until the cheese has melted and the sauce is smooth.
04 - Add the drained pasta and broccoli to the skillet with the sauce. Toss vigorously to coat everything evenly, adding splashes of the reserved pasta water as needed to loosen the sauce to your preferred consistency. Taste and adjust the seasoning.
05 - Serve immediately in warmed bowls, garnished with fresh basil leaves, an extra grating of Parmesan, and additional lemon zest if desired.