Lightly grease a 9 inch springform pan with cooking spray and set aside.
Crush the biscuits by hand or in a food processor until you get fine crumbs. Add the melted butter to the crumbs and mix together. Press down the mixture into the pan. Place in the fridge for about an hour.
If using already canned caramel, skip this step. In a saucepan melt together the butter and sugar. Once everything is melted add in the condensed milk and vanilla extract. Cook on medium low heat until the caramel starts to bubble and thicken. Stay close to the saucepan and stir frequently so that the mixture doesn’t burn and stick. Once ready, turn off the heat and let it cool completely.
Meanwhile, chop the bananas into even circles. Spread the caramel over the base and add the bananas on top. Chill in the fridge for at least an hour.
In a large bowl whip together the heavy cream and icing sugar, until you have stiff peaks. Layer it over the bananas. Chill the Banoffee pie until ready to serve. Minimum chill the pie for an hour. When ready to serve, sprinkle the pie with a generous amount of shaved chocolate.