Beat together eggs, cinnamon, and vanilla in an 8x8 dish or dish with depth to dip the bread slices into and set aside. This is your egg wash.
Crush graham crackers in a ziplock bag into tiny fragments/dust and mix with 1/2 tsp salt. Pour onto a plate and set aside.
It's time to assemble the sandwich. Spread 1/3 cup of fluff on each slice of the bread. Break Hershey bars into individual bars. Place nine pieces of chocolate on each bread slice or your preferred amount.
Press two slices together to form the s’mores sandwich. You should have two.
Dip each sandwich into the egg mixture on each side. Next, dip the sandwich into the graham cracker mixture and coat both sides.
In a medium pan or griddle over medium heat, melt 1/2 tbsp of butter.
Put the sandwich down onto the pan or griddle and cook until crispy and golden brown (about 5 minutes).
Add another 1/2 tbsp of butter to the pan and flip the sandwich onto the other side with a spatula. Cook until crispy and golden.
Repeat the same process for the second sandwich. Serve warm and enjoy!