Crush the graham crackers so there are still nickle sized pieces. Don't crush them too fine. Place them in a large bowl.
In a saucepan, add in marshmallows, butter, and molasses. Heat over medium until everything melts together and becomes a thick gooey consistency. Remove from heat.
Add vanilla and stir.
Pour the marshmallow mix into the large bowl with the graham crackers. Stir to cover all the graham cracker pieces.
Pour the graham cracker mixture into the prepared pan. Press the mixture firmly into the pan so it doesn't crumble later on.
Ganache
In a bowl, add in the chocolate chips.
In a microwave safe bowl, add in the heavy cream and microwave for 30 second intervals until the cream is hot. I would do three or four intervals. Make sure you use a bigger bowl so that the cream doesn't spill all over into your microwave.
Pour the cream into the chocolate chips and let it sit for a minute or two.
Whisk until the cream and chocolate comes together. Let it sit at room temperature for a few hours or place in the fridge for 45 minutes until the mixture thickens into almost a spreadable ganache. You want it still pourable, but pretty thick.
Pour the ganache onto the graham bars and spread. Refrigerate until ready to serve. Remove from the fridge 30 minutes before serving.