01 - Bring a large pot of generously salted water to a rolling boil. Add the pasta and cook according to package directions until al dente. Before draining, reserve approximately 1/2 cup of the starchy pasta water. Drain the pasta thoroughly.
02 - While the pasta is cooking, season the prepared shrimp with kosher salt and freshly ground black pepper.
03 - In a large skillet, heat the olive oil and 2 tablespoons of butter over medium-high heat. Arrange the seasoned shrimp in a single layer in the hot skillet. Sear for 1-2 minutes per side until the shrimp are just pink and opaque. Transfer the seared shrimp to a plate and set aside.
04 - Reduce the skillet's heat to medium. Add the remaining 2 tablespoons of butter. Once melted, add the sliced garlic and optional crushed red pepper flakes. Sauté for approximately 1 minute, stirring constantly, until fragrant but not browned.
05 - Pour the white wine or chicken broth into the skillet, using a spatula to scrape up any browned bits from the bottom of the pan. Allow the liquid to simmer and reduce slightly for about 2 minutes.
06 - Add the drained pasta to the skillet along with the reserved pasta cooking water. Toss vigorously to coat the pasta evenly with the sauce.
07 - Return the seared shrimp to the skillet. Add the lemon zest, fresh lemon juice, and chopped parsley. Toss all ingredients together until well combined and heated through, which should take approximately 1-2 minutes.
08 - Taste the dish and adjust the seasoning with additional salt or lemon juice if desired. Serve immediately, garnished with optional freshly grated Parmesan cheese and lemon wedges.