In food processor pulse biscuits until fine breadcrumbs form. You can crush the biscuits with a rolling pin
In medium bowl add the crushed digestive biscuits, melted butter, icing sugar and salt. Mix until well combined. Press the mixture firmly into your baking dish. For easier removal place cling film in the baking tin. Set aside
In large bowl using hand mixer beat cream cheese, salt and sugar until smooth and fluffy
Add avocados and beat until smooth
Add whipping cream, lime juice and lime zest. Beat until stiff peaks form
Transfer filling to the pie crust in your baking tin. Spread so that you have a smooth surface or you can create a pattern on top
Freeze the cheese cake solid for about 5-6 hours or overnight. When you want to serve let sit at room temperature for easier slicing
Enjoy
