Preheat the oven to 175 degrees celsius (347 °F). Butter and line a 24 cm loose base pie pan.
Crush the biscuits and add the melted butter. Press the mixture onto the bottom and the sides of the pan. Mix all the ingredients for the filling. Pour the mix into the pan. Bake in the middle of the oven for 10 minutes. Turn the oven off and allow the pie to cool in the oven for 30 minutes. Allow to cool to room temperature and then refrigerate for at least 4 hours or overnight.
Remove the pie from the pan and transfer onto a serving plate.
Whip the cream and add the sugar. Transfer the whipped cream into a piping bag with an open star nozzle. Decorate the pie with whipped cream pipings and some lime zest.
Find it online: https://www.emmaivane.com/en/recipes/key-lime-pie/