As someone who is fourth generation Polish in America--basically all that's left at that point is food and people butchering your last name--is that even though pirogi is plural in Polish, plenty of Americans have made pirogis the plural in English.
Try to miswrite a name of a french classic dish intentionally like you're doing here at a party or a dinner and you'll pay a heavy price in being ridiculed. I've seen this phenomenon with other things where Americans often miswrite/mispronounce names just because "it's what we call it here" and I always find it amusing.
French food is generally a different level of prestige than pirogis and gobs.
The old lady who runs our neighborhood Polish grocery store would smack me upside the head if I tried to order Pączkis!