Preheat the oven to 325°F. Add the graham crackers and melted butter to a food processor and blitz until you achieve a fine crumble. Pour the graham cracker mixture into a 9”x13” parchment lined baking dish, pressing it firmly to form a solid crust. Bake the crust for 8 minutes, then set it aside to cool.
Meanwhile, start on your ice cream base. Add the heavy cream, milk, and salt to a medium sized sauce pan over low heat. Allow this mixture to steam for 10-15 minutes. You do not want it to bubble much! If it begins to simmer, turn the heat down. We just want to steam off some of the extra moisture.
While the cream is steaming, add the egg yolks and sugar to a medium sized bowl. Whisk to combine.
Now, temper the eggs. Whisking constantly, add small spoonfuls on the hot cream to the egg yolks. Add around 5-8 spoonfuls to the egg yolks. If you rush through this step, the egg yolks will scramble! Once you’ve added at least 5 spoonfuls, pour the egg yolk mixture into the saucepan with the remaining cream. Again, whisk constantly while doing this. Add the vanilla bean paste.
Pour the ice cream base into a clean bowl and refrigerate for at least one hour, or overnight.
Once cooled, add the ice cream base to your ice cream maker. Follow your machine’s instructions, typically churning it for 20-30 minutes.
While the ice cream churns, prepare the salted caramel. Add the water and granulated sugar to a sauce pan over medium/low heat.
Once the sugar has dissolved and the mixture comes to a simmer, slowly add the butter 1 tbsp at a time. Whisk often to avoid burning, and allow the mixture to cook until you achieve a golden brown color. Once the golden color is achieved, slowly add the heavy cream while whisking. Be careful - the mixture will bubble up and fizz!
Once the cream is incorporated, remove the caramel from the heat and stir in the salt and vanilla. Transfer this to a jar and set it aside.
Once the ice cream is ready, spread it evenly over the graham cracker crust. Top with a generous drizzle of the salted caramel, then use a toothpick to marble it through the ice cream.
Melt the chocolate chips in the microwave by microwaving them for 30 seconds at a time, mixing in between each round. Drizzle the melted chocolate over the salted caramel. Sprinkle some extra flaky salt on top, and then place the entire pan into the freezer for at least 1 hour.
Remove the entire sheet from the pan by lifting from the parchment paper, and cut the sheet into bars. Enjoy!