Spray the jelly jars with cooking spray and evenly divide the crumb mixture between the jars.
Tamp the crust down evenly using a flat bottomed utensil.
For the Cheesecake:
Preheat the oven to 325 degrees.
Place the bittersweet chocolate in a small heat-proof bowl set over a pan of simmering water. Heat until just melted, stirring frequently. Set aside.
In large bowl, beat the mascarpone, cream cheese and sugar until smooth, about 3 mins. Add the eggs, one at time, beating well after each addition. Mix in the salt and vanilla.