01 - Bring a large pot of generously salted water to a rolling boil. Add the mafaldine and cook until al dente according to package directions.
02 - Three minutes before the pasta finishes cooking, add the broccoli florets directly into the boiling pasta water to blanch them until tender-crisp.
03 - Scoop out and reserve roughly ⅓ cup of the starchy pasta water, then drain the mafaldine and broccoli together in a colander.
04 - While the pasta drains, warm the olive oil and butter together in a large skillet over medium heat. Add the garlic and cook gently for about 1 minute, stirring frequently, until fragrant but not browned.
05 - Transfer the drained mafaldine and broccoli into the skillet. Toss everything thoroughly to coat in the garlic butter.
06 - Stir in the lemon zest, lemon juice, and heavy cream if using. Splash in the reserved pasta water as needed to bring the sauce together into a silky, glossy consistency.
07 - Scatter the grated Parmesan over the pasta and toss continuously until the cheese melts and the sauce clings evenly. Season with salt and pepper to taste.
08 - Divide among warm plates immediately. Finish with a scattering of fresh herbs and an extra shower of Parmesan if desired.