Spaghetti alle Vongole in Bianco Recipe

Name: Spaghetti alle Vongole in Bianco Recipe
Ingredients: Kosher salt; 3 pounds (1.25kg) fresh small clams, such as littlenecks, Manilas, or cockles (about 3 dozen littlenecks or 4 dozen Manilas or cockles); 3 tablespoons (45ml) extra-virgin olive oil, plus more as needed; 3 medium cloves garlic, very thinly sliced; Pinch red pepper flakes; 1/2 cup (120ml) dry white wine; 1 pound (450g) dried spaghetti; 1 tablespoon (15g) unsalted butter (optional); Small handful minced fresh parsley leaves