Using a nonstick spray, spray a 9x13-inch baking pan. Place aside.
Make 1-inch cubes by cutting the bread in half. Prepare a baking pan by spreading half of the cubes on it.
Beat cream cheese and confectioners' sugar together with the paddle attachment of a stand mixer or with a handheld electric mixer until smooth.
In the prepared pan, sprinkle half of the mixture evenly over the bread cubes. Add half of the blueberries on top. Afterward, layer the rest of the bread cubes on top. Sprinkle the remaining blueberries on top and drop dollops of the remaining cream cheese mixture on top. Set aside.
To make the batter, combine eggs, milk, vanilla extract, cinnamon, lemon zest, lemon juice, and brown sugar in a large bowl until completely combined.
Cover the bread evenly with the custard mixture. Put plastic wrap tightly over the bowl and place in the refrigerator for 3 to 4 hours, but overnight is better. Up to 24 hours can be kept in the refrigerator.
Preheat the oven to 350°F when you are ready to bake. Once the plastic wrap has been removed, bake for 45 to 55 minutes, until the top is golden brown and completely set.
Serve with your preferred toppings after resting for 10 minutes.