Preheat oven to 350º. Line 9X13 pan with foil and lightly spray
In a small pan, melt butter on medium high heat. Add diced onions and sauté 3-5 minutes, or until soft. Set aside to cool
In a stand mixer, add ground beef, bread crumbs, and milk. Let sit for 5 minutes for breadcrumbs to soak up the milk. Mix until just combined
Add onions, ketchup, Italian seasoning, parsley, salt, and pepper. Mix until just combined. Over-mixing the mixture will result in a dense meatloaf.
Pour mixture into foil-lined pan. Spread out until the mixture reaches the edges. Bake for 40 minutes.
While the meatloaf is baking, prepare the sauce by mixing together the ketchup, BBQ sauce, brown sugar, and Dijon mustard until a creamy mixture forms.
After 40 minutes, remove the meatloaf and soak up top layer of grease with paper towels.
Spread the meatloaf sauce over the top and return to the oven. Bake for another 10 minutes, or until the sauce is bubbly.
Remove from the oven and let sit for 10 minutes with foil on top.
Slice up and serve with sides of choice, or refrigerate to use for meatloaf sandwiches.
Enjoy!