Bring a large pot of water to a boil for the pasta.
Heat 1 tablespoon EVOO in a large skillet over medium-high heat. Add 3 tablespoons butter and melt until it foams. Add the mushrooms and brown for about 12 minutes, until golden. Add the shallots and season with thyme, salt and pepper. Stir for 3 minutes more; sprinkle in the flour, then add the Marsala and reduce for 1 minute. Add the stock and cream and simmer to thicken for a couple minutes more.
Meanwhile, in a medium size skillet, melt the remaining butter into the remaining EVOO. Add breadcrumbs and garlic and brown until nutty and fragrant. Remove from the heat, let cool for a couple of minutes, then add the cheese and parsley and season with black pepper.
When you add the shallots to the mushrooms, drop the fettuccine and cook to al dente, 8-9 minutes. Reserve a little of the starchy cooking water; drain, toss with the sauce and serve topped with breadcrumbs.