Crush the shortbread cookies into crumbs, add the melted butter, and mix.
Divide the crumbs among 6 muffin cups, press down with a shot glass, and put the base in the fridge.
In a bowl, combine the cottage cheese, egg, sugar, vanillin, and salt, and blend until smooth.
Add the cooled coffee, melted cooled chocolate, and cocoa, blend again, and divide the mixture among 6 muffin cups.
Bake in a preheated 150 °C oven for 35 minutes.
Remove the cheesecakes, let them cool, and chill in the fridge for 2 hours.