In a large pot, bring to boil the first six ingredients. Once boiled, lower the heat and cook until mixture is smooth and everything is dissolved.
Remove from heat and cool for an hour. As pot is usually hot, move mixture to another container to cool.
Start motor on ice cream maker. Pour liquid into ice cream maker and churn (See Note 1). Churn until ice cream thickens (refer to ice cream maker manual to determine time needed).
Pour 1 cup crushed graham cracker into the ice cream maker the last few minutes of churning. Once graham crackers are folded into the ice cream, stop the machine from churning.
Microwave marshmallow creme for 15-20 seconds, or until it turns into liquid.
Layer 1/5 of the ice cream onto a container. Using a knife, bring some liquid-y marshmallow creme onto ice cream and swirl it around. (See Note 2)
Repeat Step 6 until all ice cream are gone. (See Note 3) Optional: sprinkle the top of the ice cream with 2 tbsp of crushed graham cracker.
Bring ice cream to freezer and freeze for at least 5 hours.
Serve and enjoy!
Notes
Note 1: Remember to freeze freezer bowl in ice cream make at least 12 hours (or accordingly to your ice-cream manual) before preparing the ice creamNote 2: Liquid marshmallow will harden fairly quickly when it touches the ice cream. Spread out, swirl and/or shape marshmallow very quickly using the knife once you bring marshmallow to the ice cream. It is the easiest to evenly spread the marshmallow when it is in liquid form. Note 3: You may have to microwave the marshmallow several times throughout the process to keep it in liquid form.