I recommend refrigerating the tarts for a few hours to set the chocolate. However, before serving, let them come back to room temperature — the chocolate is too hard when cold.The tarts will keep for up to 3 days refrigerated.
Preheat the oven to 350°F. Place four pint-sized mason jar rings on a small baking sheet. Place the lids with the rubber part facing down.
In a food processor, combine the graham crackers and sugar. Pulse for about 30 seconds, or until finely ground. Stream in the melted butter and continue to pulse. The mixture should appear like wet sand, and it should slightly clump together when squeezed in your hand. If you over mix, it will turn into dough — not good.
Divide the graham cracker crumbs between the mason jar lids. Use a shot glass to pack in the crumbs and push them up the sides of the ring.
Bake for 10 minutes. Let cool completely on a cooling rack.
Now we’re going to melt the chocolate. It can be finicky, so this is the way I do it: Bring 1 cup of water to a boil in a small saucepan. Make sure you have a glass bowl that fits over the pan without touching the water. Place the chocolate chips and cream in the glass bowl, and have it ready next to the stove. Once the water boils, turn off the heat and place the bowl of chocolate and cream over the pan. Stir, stir, stir until the chocolate melts. You may have to turn the heat back on to boil the water again, but I find that if I’m patiently daydreaming while stirring the chocolate, it all melts just fine.
Pour the melted chocolate into the tart shells.Tap the lids gently to get rid of any air bubbles. Let sit for 10 minutes.
Dot drops of caramel sauce onto the surface of the chocolate, and after a few seconds, run a toothpick or knife through the chocolate to swirl it together.