Place half of the water in the bowl of a stand mixer. Sprinkle over the teaspoon of unflavored gelatin, set aside.

Put the remaining water, sugar, corn syrup, and salt in a small saucepan. Allow the sugar to dissolve over medium-low heat. You can gently swirl the pan to help the sugar dissolve but do not stir as this can cause the syrup to crack. Once the sugar has dissolved simmer undisturbed over medium heat until the syrup reaches soft ball stage or 240°F (115°C) when read on a candy thermometer. 

Next, pour the hot mixture into the bowl with the bloomed gelatin mixture. Whip on a low speed for two minutes to cool down the mixture. Once cool and slightly frothy add vanilla, and whip on high speed for 10-12 minutes, until the mixture is thick, white, and fluffy. 

Store Marshmallow Sauce in an airtight container in the fridge for 8 weeks. 

Using a hand or stand mixer fitted with a whisk attachment whip the cold cream on medium/ high speed until soft peaks form.

Turn off the machine and pour the condensed milk into the whipped cream.

Turn the speed up to high and whisk until the mixture is thick and stiff peaks. Turn off the machine and stir in vanilla extract and the seeds scraped from 1 vanilla pod.

Introduce a little of the ice cream base to the cooled melted chocolate to loosen it up. Then quickly introduce this to the base and mix through. Work fast or the chocolate will stiffen. Lastly, fold in crushed graham crackers.

Transfer to an air-tight sealable container and freeze for a minimum of 6 hours or overnight before eating.

Keep stored in the freezer for up to 6 weeks.