No, don’t avoid the tram, metro, or just walking around in the touristy areas where the professional pickpockets lurk. They also frequent Tram 15 that goes to Belem.
I’ve lived here for four years and, thankfully, have escaped the pickpockets - so far! Use a crossbody handbag that zips and keep your hand on it when you are on the metro, trams and walking in crowds. Lisbon is no worse than most large European cities. This is just the one where Dorie was unlucky. Remember, Rick himself was the victim of a pickpocket this year. I can’t remember where he was, but it wasn’t Lisbon.
And, yes the cake it quite lovely. There are several other places in town where you can find them. Google it before you come, so you can have it more than once!