Preheat your oven to 350°F (175°C).
Grease your muffin tin with butter or line it with muffin liners to make removal easy after baking.
Cut the loaf of French bread into small, bite-sized cubes, about 6 to 8 cups. Day-old bread works best.
In a large mixing bowl, whisk together eggs, milk, maple syrup, granulated sugar, cinnamon, vanilla extract, and melted butter until well combined.
Gently fold the bread cubes into the custard mixture, ensuring each piece is soaked. Let sit for about 10 minutes to absorb the liquid.
In a separate bowl, mix together brown sugar, all-purpose flour, extra cinnamon, and salt. Add melted butter and stir until crumbly to create the streusel topping.
Spoon the bread mixture into each muffin cup, filling about 3/4 full. Sprinkle a generous layer of cinnamon streusel on top of each muffin.
Bake in the preheated oven for 25 to 30 minutes, or until golden brown and a toothpick inserted in the center comes out clean.
Let the muffins cool in the pan for about 5 minutes before transferring to a wire rack. Dust with powdered sugar and drizzle with maple syrup before serving.