Preheat the oven to 350 degrees. In a large bowl, combine the ground beef, mushrooms, onion, parsley, thyme, breadcrumbs, egg, salt, and pepper. Mix until just blended, then shape into a loaf and place in a loaf pan.
In a small bowl, stir together the ketchup, brown sugar, and Worcestershire sauce. Spread half the sauce over the top of the meatloaf.
Bake for 50 to 55 minutes until the internal temperature reaches 160 degrees. Let the meatloaf rest for 5 minutes before slicing.
While the meatloaf rests, cook the egg noodles in boiling water according to package directions. Drain and return them to the pot. Add the butter and stir until melted and evenly coated.
Serve slices of meatloaf over the buttered noodles with the remaining sauce spooned on top.