Preheat the oven to 180 C / Gas 4. Grease and line a 20cm round loose bottomed cake tin.
Make the base by blitzing the digestives and flax seeds in a food processor, then mix with melted almond butter. Transfer the mixture to the prepared cake tin and press down to form a compacted base.
In a mixing bowl combine the cream cheese, cocoa powder, quark and protein powder with an electric whisk for 30 seconds. Combine the gelatine with the water and allow to soak for a few minutes. Place the gelatine over a pan of barely simmering water until melted then stir into the cheesecake mixture and mix thoroughly until well integrated. Spoon over the base and smooth the top.
Bake in the preheated oven for approximately 30 minutes until firm. Remove from the oven and allow to cool completely before slicing and enjoying.