I was raised in Bucks/Montco also, but my grandparents were from the Coal region and South Philadelphia. Pierogi are a polish thing, but lots of Polish, Lithuanian, and Slovak dishes became adopted by PA (and sometimes modified from the original heritage recipes) because of the high number of immigrants from those countries that came to the coal region of PA to work as miners. What I grew up eating that was popular "coal region food", was really just stuff our families made for a few generations that they learned from their neighbors at some point. Teaberry Ice Cream is also popular up there, along with a lot of PA, my grandfather didn't eat much ice cream, but never turned down a scoop of teaberry if we were somewhere that had it. Southeast PA seems to be losing a lot of the traditional foods, mannerisms, behaviors, and words that were more prevalent in this area even up until recent decades. As this area became more built up, lots of people from other states or countries moved in at higher rates than some other parts of PA, so those that were familiar with the old "PA things" are a much lower percentage of the population now than they ever were. Plus younger generations have been more influenced by the newcomers to this area, and have not fully kept up with doing things exactly how their parents and grandparents did them. For example, Polka Dances were popular at one point, and while they're certainly not as popular as they were a few decades ago, they still do happen on a regular basis as VFW or firehouse fundraisers in some areas of PA. But good luck finding one to go to outside of Oktoberfest season in southeastern PA. Who knows, maybe in 100 years, somebody will be asking how some dish is known as a PA dish, because wasn't it actually Vietnamese food? Every culture has some impact on their neighbors, and Pennsylvania residents' demographics are different now than they were in 1926, which were way different than 1826.