Sounds like they needed to bake longer. This can be the case if the slices are cut thicker.

That’s up to you – depending on how prevalent you want the flavor. I find that one side is enough for us.

I did core the pears but didn’t peel them – but neither is necessary. Some people don’t mind those parts – so it is really a personal preference. I didn’t soak them in anything either because I was working quickly. If you are doing a large batch, you could probably soak them to keep them from browning while you work. I haven’t made this recipe in quite a few years, but if I remember correctly the pears were semi-firm. I think it is a bit easier for slicing if they aren’t too soft. But that might be different if you are slicing with a mandolin vs a knife as I was using at the time.
Thanks for your questions – I’ll update the recipe with more notes.