This is probably the best ice cream I've ever made and one of the best I've ever eaten. The ice cream itself is rich and decadent and the flavors of the fillings are classic. You will want to make this and not share one single bite!
1 qt half and half (or 2 cups heavy cream and 2 cups whole milk)
Add the cocoa powder to a large, heavy sauce pot that is at least 3 quarts. Slowly add in enough half and half to make a paste. It will be clumpy and a bit difficult to mix altogether at first, but be patient, it will get there. Slowly, pour the rest of the half and half in and mix well with a whisk.
Slice the vanilla bean lengthwise and scraps the seeds out. Add the seeds and the bean to the chocolate mixture. Heat over medium-high heat until the mixture is scalding.
Take the pot off of the heat and remove the vanilla bean. Stir in the 60% and 70% chocolate. Stir until it is completely mixed. Make sure you mix well, otherwise your chocolate will be gritty. Set aside.
Whip the egg yolks and sugar until light and fluffy. While whipping fast, or on high-speed, slowly pour in the chocolate mixture, tempering the eggs.
Return the mixture back to your pot and heat on low-medium heat, stirring constantly. The mixture will thicken and should coat the back of a spoon. This takes about 5 minutes. Do not cook over 8 minutes and do not cook on a higher heat or you eggs will cook!
Pour the batter into a bowl and cover. Allow to cool in the refrigerator overnight.
The mixture should be very thick once cooled, almost like a custard. Process in your ice cream maker according to the manufacturer’s instructions. While the ice cream is churning, melt the marshmallows in the microwave for about 15 seconds. This is the easiest and least messy way to melt them!
When the ice cream is finished churning, pour half of it into a large bowl that you plan on storing your ice cream. Add half of the graham crackers, milk chocolate, and marshmallow and fold into the ice cream. Pour the rest of the ice cream into the large container and pour the rest of the graham cracker, milk chocolate, and marshmallow in. Fold these extras in as before.
Let the ice cream freeze for a few hours before enjoying.