In a small cup, mix together the cornstarch and ½ cup of the milk until smooth, and set aside.
Heat the remaining milk in a small pan over medium heat.
Slice the vanilla bean down the middle and scrape out the seeds with the back of a paring knife. Add to the milk and simmer for about 5 minutes. Remove from heat and toss out the vanilla bean.
Whisk the egg yolks in a large heat-proof bowl.
Whisk in about ½ cup of the hot milk into the egg yolks to temper them. Gradually whisk in the rest of the hot milk.
Whisk in the cornstarch mixture.
Slowly whisk in 1 cup of caramel sauce.
Return the custard to the saucepan and cook over medium heat, continuously whisking, until it thickens and a candy thermometer reads 175°F, about 5 minutes.
Remove from heat. Whisk in the butter, vanilla, and salt.
Strain the custard through a fine-mesh sieve and divide it among 6 small mason jars. Refrigerate until cool, about 4 hours.
Right before serving spoon dollops of whipped cream and a handful of crushed sugar cookies on top of each pudding.