Melt the butter in a pan and combine with the crushed biscuits, until the butter is fully absorbed.
Spread, while pressing, in a cheesecake tin (16cm). Press well so the crust is very compact. Refrigerate for an hour.
Whip cream using an electric mixer.
Add the icing sugar, cream cheese and avocado liqueur. Set aside.
Melt the agar agar for about 30 seconds in a bit of hot water. Add to the cream cheese mix and once smooth, pour onto the biscuit crust. Refrigerate for 5 hours before serving.