1. In a food processor or a Ziploc bag crush the biscuits into fine crumbs. Add melted butter and pulse until combined. Press into bottom of 8-inch (20cm) springform pan. Refrigerate while making the filling. 2. In a small bowl stir gelatin powder and water. Let bloom for 10-15 minutes. 3. Place avocado, Sweetened condensed milk, lime juice and lime zest in a food processor and pulse until completely smooth. 4. Transfer into a large bowl, add cream cheese and beat until smooth. 5. In a separate bowl whip heavy cream to stiff peaks. Fold into the avocado mixture. 6. Melt the gelatin in the microwave for 15 seconds. Temper the gelatin: Gradually add few tablespoons of the cheesecake mixture into the dissolved gelatin and stir until combined. Pour back to the cheesecake mixture and mix until combined. Pour into the springform pan, spread evenly and refrigerate overnight. 7. Whip heavy cream with powdered sugar. Transfer into a piping bag and pipe over the cake.