Mix the ground beef, breadcrumbs, egg, Parmesan, garlic, Italian seasoning, salt, and pepper in a bowl until evenly combined. Shape the mixture into a loaf roughly 8 inches long.
Lay the bacon slices on a work surface, slightly overlapping, then place the meatloaf on top. Wrap the bacon around the sides and ends, tucking the ends underneath.
Set the wrapped loaf on a rimmed baking sheet. Bake at 375°F for 45 minutes until the bacon is browned and the internal temperature reaches 160°F.
While the meatloaf bakes, bring the chicken broth to a boil in a saucepan. Whisk in the cornmeal and cook over medium heat, stirring often, until thick and creamy, about 15 minutes. Stir in the butter and keep warm.
Warm the marinara sauce in a small pan or the microwave.
Slice the meatloaf and serve each portion over a scoop of polenta with a spoonful of marinara on top.