01 - Bring a large pot of generously salted water to a rolling boil. Add the mafaldine pasta and cook according to package directions until al dente. During the last 3 minutes of cooking, add the broccoli florets to the boiling water. Reserve ½ cup of the starchy pasta water before draining both the pasta and broccoli together 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, approximately 1 minute, taking care not to let it brown.
03 - Stir the lemon zest into the garlic butter and cook for 30 seconds to bloom the citrus oils. Pour in the heavy cream and bring to a gentle simmer. Stir in the fresh lemon juice and half of the grated Parmesan cheese until the sauce is smooth and lightly thickened.
04 - Transfer the drained pasta and broccoli into the skillet with the lemon cream sauce. Toss thoroughly to coat every strand, adding the reserved pasta water a splash at a time until the sauce reaches a silky, clinging consistency. Season generously with salt and freshly ground black pepper to taste.
05 - Serve immediately in warmed bowls, finished with extra Parmesan, a bright sprinkle of lemon zest, and a scattering of fresh basil or flat-leaf parsley if desired.