Preheat the oven to 350.

Add the egg, water and unsweetened apple sauce and mix well in a bowl.

Pour the brownie mix evenly into the two graham cracker crusts and bake as you would normally for brownies, it takes a bit longer in the crusts, about 45 minutes, but start checking around the 30 minute mark with a toothpick to ensure the brownies are cooked through completely.

Remove the brownies and let them cool completely.

Preheat your broiler and break chunks of the chocolate bars on top of the brownies and then add the marshmallows.

After the broiler is preheated put the brownies on the bottom shelf of your oven. It should only take 3-5 minutes to brown the marshmallows, I suggest keeping your oven light on and watching it for those few minutes to make sure the brownies don't burn.