Gather all ingredients. Preheat oven to 350 degrees F.
Melt butter in a large skillet. Add the chopped onion, carrot, celery, and garlic. Cook for 6 to 8 minutes or until the vegetables are tender.
Add the Italian seasonings salt, and pepper. Stir to combine. Set aside for about 10 minutes or until cool enough to handle.
In a large combine crumbled Uli’s Famous Mens Room Sausage, breadcrumbs, cooled vegetables, eggs, 1/2 cup of the ketchup, fresh parsley, Dijon mustard, and Worcestershire sauce. Use your hands to mix together until everything is evenly distributed. Do not overwork.
Press evenly into 9 x 5 inch loaf pan.
In a small bowl, combine remaining ketchup with the brown sugar.
Spread about 2/3 of this glaze over the top of the meatloaf, spreading it all the way to the edges. Bake for 30 minutes.
Remove from oven and spread the remaining glaze on top of the meatloaf and bake for another 250-30 minutes until an instant read thermometer inserted into the middle of the loaf registers 160 degrees F.
Remove from the oven and let the meatloaf rest for 15 minutes before slicing and serving.
Leftovers can also be used to make great meatlaf sandwiches for lunch the next day.