Preheat oven to 375°F (190°C). Line loaf pan with aluminum foil.
Sauté chopped onion and garlic in a skillet until soft and fragrant. Let cool.
Combine ground beef, breadcrumbs, onion, garlic, egg, milk, ketchup, paprika, thyme, salt, and pepper. Mix until incorporated.
Transfer mixture to loaf pan, shape into a loaf, and arrange bacon slices on top.
Bake for 45 minutes. Brush with maple syrup and bake for another 15–20 minutes until bacon is crispy and internal temperature is 160°F (71°C).
Let rest for 10 minutes before slicing.