Important: Soak the cashew nuts in water for 8 hours.
Place all the ingredients for the crust into a blender and pulse until the crumbs start sticking together forming a dough. You would want it to remain slightly crumbly not powdery to give it some crunch.
Line the bottom of a 9 1/2 inch spring form pan with parchment paper.
Fill the dough into the spring form and press it down firmly until it forms a base.
Refrigerate the crust while preparing the filling.
Thoroughly rinse the soaked cashew nuts and add them along with the other ingredients for the filling to the blender. Blend on a low speed until the mixture is smooth, this will take about 2 minutes.
Pour the filling on top of the crust and tap the spring form onto the kitchen counter to even out the top and to release trapped air.
Cover the spring form with cling film and freeze for at least 3-4 hours.
Salted Coconut Caramel Sauce
Meantime, prepare the salted coconut caramel sauce. In a small saucepan, bring all the ingredients except for the vanilla extract to a boil and reduce the temperature. Let simmer and stir continuously while the sauce will start to thicken. It will take approximately 8-10 minutes to reduce the sauce to the desired consistency. When the sauce starts thickening taste the sauce to check for a caramel flavour. Once it develops the caramel flavour take it off the heat and let it cool. It will continue to thicken while it's cooling down. Afterwards, pour it into a squeezy bottle which makes it easier to decorate with.
Take the cake out of the freezer about one hour before you would like to serve it.
Drizzle with the salted coconut caramel sauce and top with blackberries and edible flowers if you want it to look really fancy.
If you can't source coconut cream there are multiple ways of making it yourself. Method 1: Refrigerate a can of coconut milk overnight and only use the part that has solidified on the top. Method 2: Buy creamed coconut (you get it in health food stores or most Asian markets), add boiling water to it and keep stirring until you receive a smooth texture. The desired ratio would be one part water and 2 1/2 parts hot water.