Saute the celery and onion in the same pan the sausage was in using 1/4 c. butter over medium heat until they turn translucent and onions caramelize.
Take your time, because this really gives the stuffing wonderful flavor.
Toast the bread and then cut into cubes.
Add the caramelized onions and celery, sausage, dried parsley, fennel seed, salt and pepper.
Lightly beat the egg yolks with the milk, creamed corn, chicken stock and pour slowly over the bread and seasonings, a little at a time as you stir with a large spoon until mixture is wet and not soupy. (You may not need to use all of the liquid)
Lightly grease a muffin tin with non-stick spray and fill each cup with stuffing.
Slowly drizzle with 1/2 c. of melted butter. (Use more or less, depending on how rich you want them to be.)
Bake uncovered at 350 degrees for 50 mins.
They are done when a toothpick inserted in the middle of the stuffin comes out clean.
Notes
For stuffing that is a bit more moist, you can cover with foil for the first 30 mins.