Heat the oven to 375°F. Line a rimmed baking sheet with foil and set a wire rack on top.
In a small bowl, stir together the maple syrup and Dijon mustard. Set aside half of the mixture for brushing the bacon.
In a large bowl, combine the ground beef, breadcrumbs, egg, onion, 2 tablespoons milk, smoked paprika, salt, pepper, and half of the maple-Dijon mixture. Mix gently until just combined.
Shape the mixture into a compact loaf on the rack. Lay the bacon slices across the top and sides, tucking the ends underneath the loaf. Brush the bacon with the reserved maple-Dijon mixture.
Bake until the bacon is browned and the center of the meatloaf reaches 160°F, about 50 to 60 minutes. If the bacon needs more color, broil briefly while watching it closely. Rest the meatloaf for 10 minutes before slicing.
While the meatloaf bakes, place the sweet potato chunks in a saucepan and cover them with water. Bring to a boil, then simmer until fork-tender, about 15 to 20 minutes. Drain well.
Mash the sweet potatoes with the butter, 1/4 cup milk, and 1/4 teaspoon salt until smooth. Serve the slices of meatloaf with the mash.