Preheat oven to 350 degrees. In a medium bowl, combine graham crackers and butter, and mix well. Divide equally among the 8 mason jars. Bake in preheated oven for 10 minutes, until crust gets a little crisp.

In a medium bowl, whisk egg yolks into the milk, then set aside. Combine sugar and salt in a pan over medium-high heat. Slowly add milk mixture to the sugar, whisking constantly until the mixture comes to a low boil (takes about 10 minutes).

Turn the heat down, and stir another 2 minutes, until mixture thickens. Remove from heat.

Stir in butter, vanilla, and chocolate chips, mixing well until butter and chocolate is melted and incorporated. Transfer to a bowl, cover with plastic wrap, and refrigerate for 4-6 hours.

Transfer cooled pudding into a large plastic bag, and cut off the corner. Gently squeeze the pudding mixture into the mason jars, on top of the graham cracker crust.

In a medium bowl, combine whipping cream, sugar and vanilla extract. Beat until mixture thickens to a whipped cream. Transfer to a medium plastic bag, snip the corner off the bag, and pipe the whipped topping onto each jar.