Melt the butter and crush thef regular oreos. Mix melted butter with crushed oreos and add baileys to taste (i use about 100ml).Just make sure you don't make the mixture to mushy.
Press about half (maybe a little more) of the mixture into cake springform (I use a 26cm form / about 10"). Put the crust in the fridge. Set the rest of the mixture aside.
Now melt the chocolate au bain marie.
Beat the whip cream softly (Soft peaks). Do not make it too stiff. (optional: add some more baileys to the whip cream (before beating)).
When the chocolate is fully melted add the yolks one at a time while stirring/whipping the chocolate. Use a mixer if possible. The chocolate will get hard really fast if not whipped properly.
Fold the chocolate mixture together with the whipping cream.
Put about half of the chocolate/cream mixture in the springform with the crust. Now add the rest of the oreo/butter mixture and finish with the remaining chocolate/cream mixture.
(Optional) Crush one box (about 350g) of white chocolate covered oreo's (not to hard, leave some small chunks). Sprinkle on top of the cake. Also I like to sprinkle some additional baileys on top.
Set in fridge for at least 2 hours.