Heat the remaining olive oil and 1 tablespoon of butter in a large skillet over medium heat. Add the shrimp and cook for 1-2 minutes per side until pink and opaque. Remove the shrimp from the skillet and set aside.
Add the remaining 3 tablespoons of butter to the same skillet. Add the minced garlic and red pepper flakes (if using). Cook for about 1 minute until fragrant, being careful not to burn the garlic.
Pour in the white wine or broth and lemon juice. Let it simmer and reduce slightly for 2 minutes, scraping up any browned bits from the bottom of the pan.
Return the cooked shrimp to the skillet. Toss to coat in the sauce. Stir in the fresh parsley.
Divide the zucchini noodles among serving plates. Top with the shrimp scampi mixture and spoon extra sauce over the zoodles. Serve immediately.