use granny smith apples because of their low water content. juicy apples, like McIntosh, fall apart and turn to mush (He wasn't lying. That's the worse batch I made!).
Make the batter for the French toast by whisking together the eggs, milk, vanilla, and cinnamon until evenly blended. Cover and refrigerate.
Pay close attention while you make the apples.
Put the sugar in a large, dry skillet and place it over medium-low heat.
Stir constantly with a wooden spoon until the sugar melts and begins to caramelize, about 5 minutes. Be careful; the sugar is really hot at this point.
Still stirring, add the butter, which will foam a little.
Once the sugar and butter become a caramel sauce, fold in the apple wedges. Now, because the apples are cooler than the sugar, the sugar may start to seize and harden, but don't trip out- KEEP STIRRING! Once the apples warm up the caramel will smooth out again.
When the caramel sauce loosens up and coats the apples, pour in the maple syrup.
Give it a stir and simmer for about 10 minutes, until the apples are fork tender.
Pull them off the heat and keep them warm.
For the french toast itself, warm the butter in a large nonstick skillet over medium low heat.
You'll probably only be able to fit a couple of croissants in the pan at once, so make them in batches.
Take a croissant half and dredge it quickly in the batter. Do this QUICKLY or else the croissant will disintegrate if soaked in the batter.
Lay the croissants in the pan, cut side down and cook for 4-5 minutes. Carefully flip them over with a spatula and brown the other side.
The presentation is like a caramel apple sandwich. Put the bottom half of the croissant on a plate; spoon some of the caramel apples on top of that and cover with the top half of the croissant.
Dust with confectioners' sugar and cinnamon and enjoy!