Preheat the oven to 375°F. Line a baking sheet with parchment paper or foil and then butter the lining. You could also use nonstick cooking spray.
Cut your loaf of bread into 1” strips going one direction, being careful NOT to cut all the way through. Turn the loaf and cut across your first set of cuts yielding 1” squares, still being careful not to cut all the way through. Place your cut loaf on the prepared baking sheet.
Whisk together the melted butter and milk. Stir in the sugar and then beat in the eggs 1 at a time. Then whisk in the cinnamon. I like to mix everything up in a large liquid measuring cup - it makes the next step easier.
Slowly pour the mixture in between all the cuts in the bread. Use your fingers to gently pull each cut apart while you pour so the liquid will soak in all the way through. It's fine to coat the top of the loaf a little bit as well; it serves as sort of an egg wash turning the bread a pretty golden brown.
Bake for 25-30 minutes.
When you take the loaf from the oven, drizzle the syrup over it. Crumble and coarsely chop the bacon and sprinkle it over the top. Serve warm.