Line a 22 cm baking dish with foil. Grind the biscuits in a food processor and mix with butter. Evenly distribute the resulting dough along the bottom and walls of the form. Cover with cling film and refrigerate for 1 hour. Dissolve gelatin in 0.25 cups of hot water, let cool. Beat cream cheese with sugar and vanilla essence with a mixer until smooth. In a separate bowl, whip cream into foam. Finely chop the "Mars" bars and mix with the cheese mass, adding gelatin there. Using a spatula, gradually fold in the whipped cream. Put the whole mass into a mold with dough and refrigerate for 4-6 hours.