Spread a large sheet of waxed paper on counter. Spray with non-stick spray.
Line a 15x10 inch sheet pan with foil, spray with non-stick spray.
Place crackers in pan in a single layer.
Melt butter in saucepan over medium heat. Add brown sugar.
Bring brown sugar and butter to a boil in a saucepan over medium heat. Boil 2 mintues.
Pour brown sugar mixture evenly over graham crackers in pan. Spread so it covers all the crackers evenly.
Bake at 350 degrees F for 8 minutes.
Remove and spread evenly with marshmallows
Turn oven to 400 degrees BROIL
Return crackers to oven and allow marshmallows to toast approximately 1 to 2 minutes.
Quickly remove crackers to a sheet of waxed paper that has been sprayed liberally with non-stick spray. I like to use 2 spatulas to do this.
Allow to cool.
Melt chocolate in microwave in 30 second increments, stir until smooth. Place melted chocolate in a zip-top bag. Snip tiny corner off and drizzle chocolate back and forth over the marshmallows. Allow to cool. Store in an airtight container up to 1 week.