In a large bowl, beat the cream cheese with the powdered sugar just until smooth and combined.
Add the cold heavy cream and continue beating until you get a thick, smooth filling.
Finely chop 3 Snickers bars and fold them into the filling with a spatula.
Divide the filling into 2 equal parts.
Pour the milk into a shallow bowl and warm it slightly.
Briefly dip each biscuit in the warm milk and arrange the first layer in your baking dish.
Spread the first half of the filling evenly over the biscuits.
Dip more biscuits in the milk and make a second layer.
Spread the second half of the filling evenly over the biscuits.
Add a third layer of milk-dipped biscuits on top.
For the topping, heat 100 ml heavy cream until it comes to a boil.
Chop 2 Snickers bars and the chocolate and place them in a bowl.
Pour the hot cream over the chopped Snickers and chocolate. Let it sit for 2 to 3 minutes.
Stir until smooth, then pour the topping over the cake.
Refrigerate for 2 to 3 hours, or until set.
Cut into squares and serve cold.