Preheat the oven to 350°F. Scrub the clams under cold running water to remove any sand or grit. Arrange them on a rimmed baking sheet in a single layer. Roast until the shells open, checking after 4–5 minutes and continuing as needed. Remove clams as they open. Discard any that remain closed after adequate cooking.

Allow the clams to cool until safe to handle. Remove the clam meat and roughly chop it. Reserve 24 clean clam shell halves for stuffing.

In a large skillet over medium heat, cook the bacon until almost crisp. Transfer to a plate with a slotted spoon, leaving the drippings in the skillet.

Add the onion and red bell pepper to the skillet. Cook until softened, approximately 3 minutes. Stir in the garlic and cook for 1 minute more. Add the Italian seasoning.

Remove the skillet from the heat. Add the panko breadcrumbs, Parmesan cheese, lemon zest, parsley, and chopped clams. Toss gently to combine. Season with salt and pepper to taste.

Increase the oven temperature to 450°F. Spoon approximately 1 tablespoon of stuffing into each reserved clam shell. Arrange on a baking sheet, stuffing side up. Top each with a piece of bacon and drizzle with olive oil.

Once the oven reaches 450°F, bake for approximately 5 minutes, until the topping is golden brown and the filling is thoroughly heated. Garnish with additional Parmesan and parsley, if desired. Serve immediately with lemon wedges.