Tiramisu – Should You Use Soft or Hard Ladyfingers?

For non-culinary reasons, I would offer substitutions to gelatin;

• As for a powerful stabilizer akin to gelatin but that doesn't precisely gel (go to pectin for that), when you are heating the food I have found agar to be a pretty effective stabilizer in vegan quiche that rely on a silken tofu base. I have used it to stabilize cheesecakes, pudding pies, and puree based pies and been pleased each time.

• As for a middling stabilizer/thickener, i.e. if you don't want to veer nearer to the gelatin edge, you can try tapioca flour; per Isa Chandra Moskovitz, "[sometimes tapioca flour can be used] interchangeably with corn-starch in recipes, but we feel it does have a different kind of cooked texture (thicker, gooier)."[VPITS p.7]

Well you're kinda right about it lasting a long time due to the sugar content. That will help the preserving process to the extreme. However, to be pratical you should be looking at how long the butter fat will survive in the fridge before it starts to take on funky flavours and loses it's moisture.

You'll be fine in an air tight tub for a month or so but then flavour will suffer. If you freeze it (it can be done but the quality will really suffer later) you can get away with 4-6 months before freezer burn kills it.

Honestly, I'd just do smaller batches and enjoy the higher quality product. For what you save on time doing the larger batch, you'll give up on taste and quality later.