01 - Bring a large pot of generously salted water to a rolling boil. Add the mafaldine and cook according to package directions until al dente. During the last 3 minutes of cooking, add the broccoli florets to the pot. Reserve ½ cup of the pasta cooking water before draining both the pasta and broccoli in a colander.
02 - While the pasta cooks, melt the butter with olive oil in a large skillet over medium heat. Add the finely chopped garlic and sauté until fragrant, about 1 minute. Take care not to let the garlic brown, as it will turn bitter.
03 - Stir in the lemon zest and cook for 30 seconds to release its essential oils. Pour in the heavy cream and bring it gently to a simmer. Add the lemon juice and half of the grated Parmesan, stirring until the cheese melts and the sauce is smooth.
04 - Transfer the drained pasta and broccoli to the skillet with the sauce. Toss everything together thoroughly, adding the reserved pasta water a splash at a time until the sauce is silky and evenly coats every strand. Season generously with salt and freshly ground black pepper.
05 - Serve immediately in warm bowls, garnished with the remaining Parmesan, a generous sprinkle of lemon zest, and fresh chopped basil or parsley if desired.