Preheat your oven to 375°F (190°C). Prepare a loaf pan by greasing it lightly or lining with parchment paper.

In a skillet over medium heat, heat olive oil and sauté onions and garlic until soft and translucent, about 5 minutes. Allow to cool.

Combine the ground beef, breadcrumbs, eggs, milk, Worcestershire sauce, Dijon mustard, ketchup, salt, black pepper, smoked paprika, and cooled onion-garlic mixture in a bowl. Mix gently until just combined.

Transfer the mixture into the prepared loaf pan and shape it into a tight, even loaf. Smooth the top with a spatula.

In a bowl, whisk together glaze ingredients: ketchup, brown sugar, Dijon mustard, Worcestershire sauce, and apple cider vinegar until smooth.

Spread a layer of the glaze evenly over the top of the meatloaf before baking.

Bake uncovered for 45 minutes, brushing on more glaze after 20 minutes for a rich topping. Ensure the internal temperature reaches 160°F (71°C).

Let the meatloaf rest for 10 minutes in the pan before slicing and serving warm.