We’ve made a fair amount of ice cream this summer, and the kids have been on ripple benders, so I am not unfamiliar with multi-process ice cream making. This was more of a pain in the ass than most home-made ice creams. But worth it.
Also, I'll probably come back and edit this recipe as I remember odds and ends.
2 cups whole milk
1 cup heavy cream
1 vanilla bean
pinch of salt
¾ cup sugar
3 egg yolks
2 Tablespoons Kahlua/other coffee-flavored liqueur
4 oz marscapone
1 Tablespoon Kahlua mixed with 1+ Tablespoon water
4 ladyfingers (I buy them)
Mocha ripple (I make a fudge ripple and whisk in instant espresso granules to taste)
Unsweetened cocoa powder, about ½ teaspoon
I find it handy to have someone else in the kitchen when making ice cream custard. If I remember that I forgot to make an ice water bath to cool the custard in while I’m cooking the custard, an extra pair of hands is convenient (to either make the ice water bath or stir the custard) so that I do not end up with scrambled egg ice cream. Scrambled egg ice cream annoys the hell out of me, particularly since it is far more expensive than Ben & Jerry's.
1. In a heavy pan, heat 1.5 cups of the milk and ½ cup of the cream with ½ cup of sugar, the salt and the vanilla bean (split, scraping the seeds from the bean into the milk mixture). Heat until steaming and the sugar is dissolved, and then remove it from heat and pop a lid on it and let it steep for about half an hour. You shouldn’t bring it to a boil (why? I don’t really know. That just seems to be the general consensus of people who know more about ice cream making than I do), but I did by mistake, and the sky didn’t fall.
2. In a bowl that accommodate the milk mixture, whisk the egg yolks with the remaining sugar. When the ½ hour of dairy/vanilla steeping has finished, slowly pour the milk mixture into the egg mixture, whisking all the while so that you do not have scrambled egg tiramisu ice cream.
When this mixture is all tempered and whisked together, pour it back into the pan and cook, stirring carefully all the while, over low to med-low heat until it is steaming profusely and it coats the back of a spoon when you dip it in (you'll be able to draw a line across the back of the spoon with your finger and have it stay put).
3. Meanwhile, magically make an ice water bath for cooling the custard (you could probably do this right before you stir the milk mixture into the egg yolks and sugar. I do not usually think of step 3 until I am done with step 2, even if I have read the recipe twice in advance). In a mixing bowl that will then go into the ice water bath, pour the remaining cream and milk. Put a strainer on the bowl. When the custard on the stove is ready, remove from heat, and pour through the strainer into the bowl with the cream and milk. Stir it all together, and place in an ice water bath, stirring all the while, to stop the cooking. I usually lose patience with this step once the custard gets tepid, and then I put saran wrap on it and put in the refrigerator until it’s cold.
4. When the mixture is cold and ready to churn, mix 2 Tablespoons of Kahlua (or some other coffee-ish liqueur) with the marscapone and stir the cold custard in slowly, so that there aren't big lumps of marscapone. Put the whole thing into the ice cream maker and start churning.
5. While the ice cream is churning, break the ladyfingers into pieces. Sprinkle the kahlua/water mix onto them and let them sit while the ice cream churns.
6. When the ice cream is done churning, put a scoop across the bottom of the container you will be using. Drizzle it with mocha ripple. Sprinkle on ladyfingers, and very lightly, dust with the unsweetened cocoa powder (I found I didn’t quite use the ½ teaspoon). Put another layer of ice cream on top, and repeat, finishing with a layer of ice cream, which, if you’re feeling like making it look like regular tiramisu, you can sprinkle with cocoa powder.