Bring a large pot of salted water to a boil and add the penne pasta, cooking until just al dente—about 2 minutes less than package directions. Reserve about a cup of starchy pasta water before draining, then set aside.
While the pasta cooks, cut the broccoli into small florets. Blanch in boiling water for 2-3 minutes until bright green and tender but still crisp. Transfer immediately to an ice bath to halt cooking and preserve vibrant color.
Heat the olive oil in a deep skillet over medium heat until shimmering. Add the finely chopped garlic and sauté for about 30 seconds until fragrant and lightly golden—avoid burning to prevent bitterness.
Add the blanched broccoli florets to the skillet and toss gently to coat with the garlic oil. Cook for another 2 minutes until the broccoli smells nutty and starts to slightly roast at the edges.
Pour in the heavy cream and stir constantly, allowing it to simmer gently for 3-4 minutes until slightly thickened and silky. It should coat the broccoli evenly without boiling vigorously.
Add the cooked, drained pasta directly into the skillet. Toss everything together using tongs or a large spoon, adding reserved pasta water gradually to loosen the sauce and achieve a glossy, velvety texture.
Finish by zesting the lemon directly over the pasta, then squeeze in the lemon juice. Season with salt and freshly cracked pepper to taste. Toss again to distribute the flavors evenly.
Transfer the creamy broccoli pasta to serving bowls immediately. Optional: sprinkle with grated Parmesan cheese for added depth. Serve hot, enjoying the bright, velvety, and crisp-tender harmony.
