Heat oven to 400°F. Lightly oil a 12-cup muffin pan.
Stir breadcrumbs and milk in a bowl. Let the mixture soak 5 minutes.
Add ground beef, beaten egg, onion, garlic, ketchup, Worcestershire, and Dijon to the bowl.
Sprinkle in parsley, Parmesan, paprika, salt, and pepper. Mix gently until just combined.
Line each muffin cup with a strip of bacon, covering sides and bottom.
Divide meat mixture into 10–12 portions. Press into the bacon-lined cups.
Whisk glaze: ketchup, brown sugar, vinegar, and Dijon until smooth.
Brush a spoonful of glaze over each mini meatloaf.
Bake 20–25 minutes, until bacon is crisp and centers reach 160°F.
Rest 5 minutes. Brush with extra glaze and serve warm.