Preheat your oven to 350°F (175°C) and line a 9x5 inch loaf pan with parchment paper.

Sauté the diced onion and minced garlic in olive oil over medium heat until softened, about 5 minutes.

In a large bowl, combine the beaten eggs, whole milk, seasoned breadcrumbs, grated Parmesan, and the onion-garlic mixture; let it sit for 5 minutes.

Gently add the ground beef and pork to the mixture, mixing until just combined.

Press the meat mixture into the prepared loaf pan without overpacking.

In a separate bowl, whisk together the BBQ sauce, honey, grape jelly, vinegar, and mustard, reserving a third for later.

Bake the meatloaf for 45 minutes, then apply one-third of the glaze over the top and return to the oven.

Bake for an additional 25-30 minutes until the internal temperature reaches 160°F (70°C).

Remove from the oven, let rest for 10 minutes, and serve with the remaining glaze.