Bring a large pot of salted water to a rolling boil. Add penne pasta and cook until just al dente, about 10 minutes. Drain, reserving ½ cup of pasta water, and set aside.
While the pasta cooks, season the shrimp with salt and pepper. Heat a large skillet over medium-high heat, add olive oil, and once shimmering, add the shrimp in a single layer. Cook for 2-3 minutes per side until pink and opaque, then remove and set aside.
In the same skillet, melt butter over medium heat and add the minced garlic. Sauté for about 30 seconds until fragrant and golden, filling the kitchen with a warm, nutty aroma.
Pour in the heavy cream and bring to a gentle simmer, stirring constantly. Let it simmer for 2 minutes until it slightly thickens and starts to coat the back of a spoon.
Gradually stir in the grated Parmesan cheese, mixing until the sauce is smooth and creamy. Season with additional salt, pepper, and a squeeze of lemon juice if desired for a bright contrast.
Return the cooked shrimp to the skillet, tossing gently to coat them in the sauce. Add the cooked penne pasta and toss everything together over low heat for 1-2 minutes, allowing flavors to meld and sauce to cling beautifully.
Taste and adjust seasoning as needed. The sauce should be silky and glossy, coating each piece of pasta and shrimp evenly. Serve immediately, garnished with extra Parmesan and fresh parsley if desired.
