This i probably some you have tried already, otherwise a tip for thanksgiving http://www.seriouseats.com/recipes/2011/03/beeramisu-guinness-tiramisu-st-patricks-day.html
Unfortunately that beer is not available in Norway, so I have not tasted it. Based on the review it gets here on BA, it should work.
A friend of mine has made that several times. It's the only good use for Southern Tier Creme Brûlée stout.
I only use it for the mascarpone component - I use an espresso stout to soak the ladyfingers in. And it is really a good flavor for that application. Anything else - not so much!
A fellow member of our local homebrew club makes a mean Beeramisu with Santa Fe brewing company's Imperial Java Stout. I always go for that when he brings it for potlucks.
I made my own Irish cream, and made this recipe with Terrapin's Wake n Bake, and it was pretty dang good.. Not like the real thing, but pretty goood for a quick recipe.
I've made Beeramisu many, many times. It's kind of my thing and "known" for making some amazing variations. It also helps that I'm a chef by trade. There are certain flavor profiles that Tiramisu should have. Coffee, chocolate, creamy mascarpone and "booze". The booze is very important as it helps cut and balance the sweetness from everything else. Traditionally Marsala wine is used but often is substituted with rum, Madeira, port, or brandy. The beers I like to use is a boozy barrel aged stout or porter like Parabola (my personal favorite), Bourbon County, Anderson Valley Huge Arker, and many others. If you don't have access to barrel aged beers then you can use a stout and use the liquor of your choice from above.
I like dipping the lady fingers in a strongly-flavored espresso stout, but sticking with Triple Bock or Samichclaus for the mascarpone component.
