Cook the pasta according to package instructions. Reserve 1/2 cup of pasta water and drain the rest. Set aside.

Heat olive oil and 2 tablespoons of butter in a large skillet over medium-high heat. Add the shrimp in a single layer, season with Cajun seasoning, and cook for 1–2 minutes per side, until pink and opaque. Remove shrimp and set aside.

In the same skillet, add the remaining butter, minced garlic, and crushed red pepper flakes (if using). Sauté for about 1 minute until fragrant.

Pour in the white wine or chicken broth, scraping up any browned bits from the bottom of the skillet. Let the liquid simmer for 2–3 minutes to reduce slightly.

Stir in the lemon juice and half of the chopped parsley. Add the cooked pasta to the skillet, tossing to coat in the sauce. If needed, add a splash of reserved pasta water to loosen the sauce.

Return the shrimp to the skillet and toss gently to combine. Cook for another minute to heat everything through. Adjust seasoning with additional Cajun seasoning, salt, and pepper to taste.

Serve immediately, garnished with the remaining parsley and lemon wedges.