I have been given the recipe for lill' B which is the base beer for many of the evil twin stouts. I was asked not to share it by Jeppe so I will need to respect his wishes. That said I can give you a few key price of advice.
First off think it as an imperial porter and not imperial stout, use debittered roast malts only.
You need a significant amount of layered malty type malts such as aromatic and crystal malts of different colours.
Do not be modest in addition of speciality malts in both variety and amount. Many people will suggest you go for a simple grain bill, whilst I do not diaagree with this sentiment it's not how the Evil twin beers are made.
I did not inquire regarding the yeast that the use but I had good success with WLP007.