Preheat griddle to 325 degrees.
Beat together 2 eggs, milk and vanilla. Whisk in cinnamon.
Soak the croissant halves in the custard for a few seconds until they have soaked up the custard.
Lightly coat the griddle with butter or oil. Add the croissants and cook for 2 to 4 minutes per side until deeply golden.
Beat remaining 2 eggs with 2 t water until frothy. Heat a nonstick skillet over medium heat and melt in a little bit of butter. Pour in the eggs. Stir gently with a rubber spatula or spoon. When the eggs start to form curds, add the cheese. When the eggs are just about done, stir in the bacon so it gets incorporated.
Place egg mixture on top of bottom croissant half. Sprinkle with any extra bacon. Add top half of the croissant. Drizzle with maple syrup.
Enjoy.