Whip the cream until stiff, add the sweet condensed milk and mix well. Dissolve the gelatine according to the instructions and add to the cream mixture. Crumble the biscuits finely, put some of them in a springform pan (24 or 26 cm diameter) and cover the bottom with the crumbs about an inch thick. Pour the cream mixture on top and cover everything with the remaining biscuit crumbs.