Preheat the oven to 180°C and line a springform pan (20 cm diameter) with parchment paper or grease the pan.
Place the walnuts in a food processor and grind into a fine meal.
Add sugar, flour, and salt and pulse until combined.
Add coconut oil and blend until the dough holds together.
Now knead in the whisky.
Press dough into bottom and sides of the pan and place in the fridge.
To prepare the filling, place all ingredients in a blender and process until smooth.
Remove the prepared springform pan from fridge and pour filling into the crust.
Bake for 70 minutes or until filling is golden brown and has set.
10 minutes before you remove the cake from the oven prepare the topping: Place all ingredients in a small saucepan and cook over high heat for five minutes, stirring constantly.
Set aside and let cool for another five minutes.
Remove the cake from the oven and spread topping on top.
Let cool to room temperature and then let the cake set in the fridge for 3-4 hours before serving.