If making fresh ice cream, make the custard first. In a medium saucepan, combine 1 cup of the cream with the cocoa powder. Warm over medium-high heat, whisking to dissolve the cocoa. Bring the mixture to a boil, then reduce the heat to medium-low and let simmer for 30 seconds, whisking constantly. Remove the pan from the heat, mix in the chocolate and whisk until melted and smooth. Stir in the remaining 1 cup of cream. Transfer this mixture to a medium-large mixing bowl. Set a fine mesh sieve over the top.

In the same saucepan, combine the milk, sugar and salt and warm the mixture over medium-high heat. In a medium mixing bowl, whisk together the egg yolks. When the milk mixture is warm, gradually whisk the milk into the egg yolks, beating constantly. Return the egg-milk mixture to the saucepan and continue heating over medium-high heat, stirring constantly and scraping the bottom of the pan with a spatula, until the mixture is slightly thickened and coats the back of a spoon. Remove from the heat, pour through the mesh sieve into the chocolate-cream mixture and stir to blend. Stir in the vanilla extract. If needed pour ice cream back through the strainer one more time. I did this, but only because I had bits of chocolate that must not have properly melted.

Cover with plastic wrap and chill the mixture in the refrigerator for several hours or overnight (I stuck mine in the freezer to speed things up). Once the ice cream mixture is well chilled, freeze in an ice cream maker according to the manufacturer’s instructions.

While your ice cream turns or softens on the counter, toast the marshmallows. Preheat the broiler to high. Spay a baking sheet with cooking spray and spread the marshmallows out in a single layer. Try and not let the marshmallows touch each other. Broil for 30 seconds to 1 minute, watching very closely! Remove and let cool for a few minutes and then break any apart that melted together. While the marshmallows cool make the fudge sauce. Place the butter, sweetened condensed milk and chocolate chips in a small sauce pot. Heat on medium low until melted and smooth. Stir in the salt.

When the ice cream is done churning or softening gently fold in the chopped graham crackers and marshmallows with a rubber spatula. Spoon some of the fudge sauce onto the bottom of your storage container. As you remove the ice cream from the machine or from the carton, layer generous spoonfuls of the sauce between layers of the ice cream, ending with a top layer of ice cream. Do not stir the fudge into the ice cream, as it will make the ice cream very soft. Freeze until the ice cream is firm, at least 2 hours.