Bring a large pot of water to a boil. Add a generous amount of salt (it should taste like seawater) and cook the pasta according to package directions until al dente. Before draining, reserve 1 cup of pasta water—this starchy liquid is liquid gold for your sauce.
While the pasta cooks, prep your shrimp. Pat them dry with paper towels (wet shrimp = sad, steamed shrimp instead of nicely seared ones). Season with salt and pepper.
Heat your showtime skillet. In a large skillet over medium-high heat, add 2 tablespoons of butter and 2 tablespoons of olive oil. When the butter starts to foam but before it browns, add the shrimp in a single layer.
Cook those shrimp perfectly. Let them sear for about 1-2 minutes per side until they're pink and opaque. Don't overcook them unless you enjoy the texture of rubber bands. Remove to a plate and set aside.
Create flavor town. In the same skillet, reduce heat to medium and add the remaining 2 tablespoons each of butter and olive oil. Add the minced garlic and red pepper flakes, stirring constantly for about 30 seconds until fragrant but not browned. Burned garlic will ruin your day faster than stepping on a Lego.
Deglaze like a pro. Pour in the white wine (or broth) and use a wooden spoon to scrape up all the delicious browned bits from the bottom of the pan. Let it reduce by half, about 2-3 minutes.
Add the brightness. Stir in the lemon juice and zest. If going for the creamy version, add the heavy cream now and let it simmer for a minute.
Bring it all together. Add the drained pasta directly to the sauce in the skillet. Toss well to coat, adding splashes of that reserved pasta water as needed to create a silky sauce that clings to the pasta. Start with a little—you can always add more.
Return the shrimp to the skillet along with any accumulated juices (flavor!). Add the Parmesan cheese and parsley, tossing gently to combine. Taste and adjust seasoning with salt and pepper.
Serve immediately with extra Parmesan, a sprinkle of parsley, and some fresh cracked pepper. Twirl that fork and prepare for compliments.