Place an oven rack in the middle of the oven. Preheat the oven to 350 degrees F. Butter a 9 by 13-inch baking dish. Set aside.
In a large bowl, beat the eggs until frothy. Add the milk, maple syrup, cinnamon, salt, and lemon zest. Add the bread cubes and mix until coated. Stir in the blueberries. Pour the mixture into the prepared baking dish.
In a small bowl, mix together the remaining cinnamon and sugar. Sprinkle the cinnamon sugar over the egg mixture in an even layer. Bake for 40 to 45 minutes until the top is golden and the filling is set.
Spoon onto serving plates and drizzle with maple syrup.
Recipe courtesy of Giada De Laurentiis