Bring a large pot of salted water to a boil. Drizzle in olive oil and add fresh herbs if desired. Add the spaghetti and cook until tender, about 9–11 minutes. Reserve 240 ml of pasta water. Drain and set aside.

While the pasta cooks, rinse and pat dry the prepared shrimp. Make sure they are completely dry to ensure proper browning when cooked.

Melt the butter in a large skillet over medium heat. Add shrimp and cook until beginning to turn pink and curl, about 2–3 minutes. Be careful not to overcrowd the pan as this will cause the shrimp to steam rather than sauté.

Add minced garlic to the skillet. Continue sautéing with the shrimp for 5–7 minutes until shrimp are pink and opaque. The garlic should become fragrant but not brown, as this can create a bitter taste.

Drizzle in remaining olive oil. Add cooked pasta to the skillet with shrimp. Sprinkle in Italian seasoning, black pepper, red pepper flakes, and salt. Pour in 60 ml of reserved pasta water to moisten, adding more as needed. The starchy pasta water helps create a silky sauce that coats the pasta.

Toss mixture thoroughly over medium heat until pasta is evenly coated and heated through. Garnish with additional fresh herbs if desired and serve immediately for the best flavor and texture.