Bring a large pot of salted water to a boil. Add 8 oz of penne pasta and cook according to package instructions until al dente, usually about 10-12 minutes. Drain and set aside, reserving a half cup of pasta water for later.
Heat 3 tablespoons of olive oil in a large skillet over medium heat. Add the minced garlic and cook for about 1 minute until fragrant but not browned.
Add the peeled and deveined shrimp and season with salt and pepper. Cook for 2-3 minutes on each side until the shrimp turn pink and opaque. Remove the shrimp from the skillet and set aside.
In the same skillet, pour in 1 cup heavy cream. Stir well to combine with the garlic-infused oil. Add the lemon zest and juice of 1 lemon, stirring constantly to blend the flavors. Let it simmer gently for 3-4 minutes to thicken slightly.
Reduce the heat to low. Stir in 1/2 cup grated Parmesan cheese until melted and smooth. Taste the sauce and add salt and pepper as needed. If the sauce feels too thick, add a splash of the reserved pasta water to loosen it up.
Return the cooked shrimp to the skillet, then add the drained penne pasta. Toss everything together until the pasta is fully coated in the creamy lemon garlic sauce and the shrimp are evenly distributed.
Sprinkle freshly chopped parsley over the top for a burst of color and freshness. Serve immediately and enjoy the delightful blend of creamy, tangy, and savory flavors.