Cube the loaf of bread into roughly 1-inch pieces and spread evenly in a greased 9×13-inch baking dish.
Beat the softened cream cheese with a hand or stand mixer until completely smooth and creamy.
Whisk together eggs, milk, sugar, vanilla extract, and ground cinnamon in a separate bowl until well combined.
Gently fold the custard mixture into the whipped cream cheese until smooth.
Pour half of the custard mixture over the bread cubes and toss gently to coat evenly.
Sprinkle 1 cup of blueberries on top, then pour the remaining custard mixture over everything and top with the remaining blueberries.
If using, sprinkle the cooked and crumbled turkey bacon over the top now.
Cover the baking dish tightly with plastic wrap and refrigerate overnight or for at least 4 hours.
Preheat oven to 350°F (175°C). Remove plastic wrap and bake uncovered for 45-50 minutes until golden brown and custard is set.
Let cool a few minutes, dust with powdered sugar, and serve warm, optionally with maple syrup or whipped cream.