How to Make a Chocolate Ice-cream sandwich biscuit?

Dear all

I am trying to produce a chocolate biscuit for the use with ice cream, most importantly it should have the cake like texture when added to icecream.

Firstly, I do not know if this type of biscuits is made with rotary moulders or with hard biscuit machine like marie biscuit.

So I tried both, but for rotary moulders, the biscuit kept on developing cracks the next day (cooling time is 2 times oven time) and also did not absorb enough water from the icecream to make the cake like texture needed. (It was left frozen with the icecream for more that 3 days).

For hard biscuit, the I could not make the biscuit taste chocolaty enough, as when I increase the amount of cocoa powder the dough becomes less elastic. And also did not make the cake like textured desired after freezing it with icecream for more tha 3 days.

Thank yoy for your help