2.Now add the custard milk. Stir slowly, well and continuosly.The mixture gets thickened very fast so be very careful. Stir for 2-3 mins switch off and cool down. The consistency is little thicker, but still should be in flowing consistency as shown below. Now dip each biscuit for a second and arrange it in a square plate/tin and layer the base of the plate with krack jack biscuits dipped in coffee decotion for first layer.
3.Above the first layer spread a generous spoon of prepared custard then layer another set of biscuits dipped in coffee decotion.Repeat this with another layer then alternatively stack up with biscuits and custard. Build 3-4 layers repeating the same process.Then grate chocolate/ add chocolate sauce or readymade choc semiya(which is what I've done) over the top layer biscuits, covering up the whole cake.
4.Refrigerate it for few hours (about 2-3 hrs). Remove from the fridge about 5-10 minutes before serving.Cut into desired squares/pieces and serve immediately.