To make this even easier I decided to use Golden Grahams instead of regular graham crackers. That way you don't have to break up the graham crackers and further each bite has uniform pieces.
The key to this is to use a piece of parchment on a half sheet pan to make sure that nothing sticks.
Spread out 4 cups of the golden graham cereal onto the parchment lined half sheet pan.
Next sprinkle 1 cup of milk chocolate chips over the top. Make sure to get milk and not semi-sweet chips.
Next sprinkle 1 cup of mini marshmallows over the top.
Now it is time to melt the chocolate. Add the remaining chips from the 12oz bag into a microwave safe bowl and slowly melt. I melted mine by cooking them in the microwave for 1 minute at 70% power. I removed and stirred. Then I put the chips back into the microwave for more seconds at a time at 70% power until the chips were fully melted. Make sure to stir and not to overheat.
Once the chocolate is melted drizzle it over the top of the cereal, chips and marshmallows. It does not have to be perfect. Try to cover as much as you can.
While the chocolate is still warm sprinkle 1 more cup of mini marshmallows over the top. Then refrigerate to cool and let it set.
Once the chocolate is cooled and set, you can break it up into little chunks and store it in a zip top bag.