For the toasted breadcrumbs: Preheat the oven to 400 degrees F. Cut the baguette into large cubes. Add to a food processor and pulse until processed into crumbs. Spread the crumbs out on a baking sheet and toss with some olive oil, salt and pepper. Transfer to the oven and toast until golden brown, stirring as needed to evenly brown, 5 to 10 minutes.
For the clams: Add the clams, 2 tablespoons of the chopped Calabrian chiles, garlic, onion, two of the thyme sprigs, white wine, 1 cup water and some kosher salt to a saucepan. Cover with a lid, bring to a boil, and cook just until the clams open, 5 to 10 minutes. Remove the clams from the broth with tongs and allow to cool. Reserve the clam broth. Discard any clams that haven't opened. Once the clams have cooled, remove from shells and chop. Set aside.
For the sauce: To a large high-sided saute pan, add the butter and 1 tablespoon olive oil and allow the butter to melt. Once melted, add the remaining 2 tablespoons chopped Calabrian chilies and the remaining 2 thyme sprigs, along with a ladleful or two of the clam broth. Bring to a boil. Add a touch of cream and the chopped clams, stirring until just combined. Remove the thyme sprigs. Taste and adjust the seasoning as needed.
Add the cooked pasta to the sauce, along with more broth if needed, and toss.
Serve in a bowl, garnished with chopped parsley and toasted breadcrumbs.