Grind the Marie biscuits into a fine crumble in a mixer or alternately put them in a ziplock bag and crush with a rolling pin.
In a bowl beat the chilled cream with a hand mixer till standing peaks are formed ,it will take around 2-3 minutes.
Add the condensed milk and vanilla extract and mix till incorporated nicely.
Arrange a layer of crushed biscuits in the dessert glass,then pipe the cream and condensed milk mix into the glasses with a piping bag to facilitate neat layering or arrange the the mix on the biscuit layer with a spoon.
Repeat the process till the rim of the glass ending with either the cream or biscuit crumble.
Garnish with chocolate shavings and chill in the fridge for nearly 3 hours.Once ready, Serve.