Place the 500 g fresh arselle clams in a large bowl with cold water and 1 tablespoon salt. Leave them to purge sand for 60 minutes.

Drain the arselle clams in a colander. Rinse them thoroughly under cold running water.

Finely chop the fresh parsley. Peel and lightly crush the garlic cloves.

Heat 2 tablespoons extra virgin olive oil in a large skillet over medium-high heat. Add the garlic, chili pepper, and half of the chopped parsley.

Add the drained arselle clams to the skillet. Cook until the shells open, about 4 to 6 minutes.

Pour 120 ml dry white wine into the skillet. Simmer for 2 minutes, then remove the opened clams from the heat.

Remove the clam meat from most shells, keeping a few whole clams for garnish. Discard any clams that did not open.

Strain the clam cooking liquid through a fine-mesh sieve into a large pot. Add enough water to make about 1.5 l of hot cooking liquid.

Bring the strained clam liquid to a gentle simmer. Add the 400 g spaghetti to a clean large skillet.

Ladle hot clam liquid over the spaghetti until barely covered. Cook while tossing frequently and adding more liquid as it absorbs.

Continue cooking the spaghetti until al dente and creamy, about 10 to 12 minutes. Season with black pepper.

Add the shelled clam meat and reserved whole clams to the spaghetti. Toss gently for 1 minute to warm them through.

Remove the skillet from the heat and drizzle in the remaining 1 tablespoon extra virgin olive oil. Toss until the sauce turns glossy and creamy.

Top with the remaining fresh parsley. Serve immediately while the spaghetti is creamy.