How to cook
Put the biscuits in a blender with the butter and blend them finely. If you don't have a blender, put them in a bowl and crumble them finely, melt the butter and add it, stir until you get a biscuit dough.
Crumble the hazelnuts, so you have both coarse and fine pieces. Put them in with the biscuits and stir well.
Use this mixture as the base for your cheesecake. If using a form, distribute it along the bottom (I used cups/small jars). Press the mixture down to the bottom well. Put it in the fridge for 20 min. to harden.
Distribute the cream on top of the biscuit base, in the form or cups, and put it in the fridge again for a few hours.
Finally, cover the cheesecake with blueberry jam. Optionally, use any other kind of jam or chocolate. Consume well cooled.