Crush the butter biscuits properly. Please do not crush them completely.
Melt the butter.
Mix crumbly biscuits with za'atar and butter and place in a springform pan lined with baking paper, spreading with your hands and pressing down a little.
Bake the base in the oven for approx. 10 minutes.
Cream cheese mixture
Mix all the ingredients together. Please do not beat, as this will cause air to rise. The cake would then rise and collapse at the end. Mix everything slowly until it becomes a creamy mixture.
Bake cheesecake
Pour the cream cheese mixture onto the biscuit base and carefully smooth it out.
Bake the cheesecake for approx. 40 - 45 minutes at 180 °C in a preheated oven. Then allow to cool completely.
Sumac berries
Combine berries (defrosted if frozen) with sugar in a saucepan and bring to the boil briefly, then simmer over medium heat for about 5 minutes.
Add the sumac and rose water and mix well.
Garnish cheesecake
Serve the sumac berries with the cheesecake or spread them directly on top. Garnish with chopped pistachios if desired.