Preheat oven to 350 F.
Put graham crackers in the small bowl of the Magimix fitted with the metal blade, and pulse until fine crumbs form. Add the melted butter and sugar and pulse to blend.
Transfer mixture to a small bowl. Stir in the chocolate. Divide mixture equally among 12 round molds in a mini cheesecake pan, pressing evenly into the bottom of each cup.
Bake until lightly browned, about 10 minutes. Cool.
Put all ingredients in the large bowl of the Magimix fitted with the metal blade and pulse until smooth. Scrape bowl and pulse again. Pour mixture onto the cookie crusts in the mini cheesecake pan, dividing evenly and filling almost to the top.
Bake until set, about 15 minutes. Remove from oven and let cool completely. Transfer to the refrigerator and chill thoroughly.
Remove cheesecake pan from the refrigerator approximately 15 minutes prior to serving. Carefully unmold the cheesecakes from the pan.
In a small bowl, stir together the sugar and the salt. Put the egg whites and sugar mixture in the large bowl of the Magimix fitted with the whisk attachment and beat until stiff peaks form. Spoon meringue into a piping bag fitted with a medium star tip.
Pipe a large star on the top of each cheesecake. Using a kitchen torch, lightly torch the top of the meringue "star", browning slightly.
Shave chocolate on top of meringue for garnish.
Makes 15 miniature cheesecakes.