Prepare an 8-inch round springform pan by covering the sides with parchment paper. Keep aside.
Break each Marie biscuit into 5-6 pieces. Do not crush them into small pieces. Keep aside.
Pudding: in a saucepan, add milk, sift into it cocoa powder and corn flour.
Then add sugar, oil and vanilla.
Whisk well to get rid of lumps.
Cook on medium to low, stirring continuously until the pudding is thickened and has “ribbon-like” pouring consistency. If its too thick you can add a little milk and mix. Take the pudding off the flame.
In a big bowl, add the biscuits. Pour the pudding and mix quickly to coat the biscuits in pudding. Do not over mix otherwise cookies will become soft and mushy.
Pour into the prepared mould.
Decorate the cake with leftover cookie crumbs.
Refrigerate for at least 5-6 hours or preferably overnight.