One thing that seems strange to me is the use of 果子 (guǒzi) meaning fruit, when there is no fruit in 煎饼果子.
Question: Why is 果子 in 煎饼果子 (jiānbǐng guǒzi)?
"果子" is a regional name for "糖果糕點" - any sugar, rice or wheat flour-based food that is not a staple food. This broad category includes sweet and savoury items, cakes and candy.
The 果子 in 煎饼果子 refers to the 油条 wrapped inside. Of course, regional varieties of the food can have different fillings.
I love 煎饼果子 too!
You know what 油条 is. One of my American friends interpreted it as "straight salty donut".
煎饼果子, in fact, is 煎饼 + 油条.
In northern areas, we call 油条 大果子. I don't know why.
Then we got 煎饼果子.
Just want to add some supplementary info as a Chinese who lived in Tianjin for a few years. You usually got two options for 煎饼 in Tianjin:
I believe the word 果子 is actually originated from 馃子. However, it seems to be used only with 煎饼 in Tianjin, and I've never seen such usage in any other region.
The correct writing is 煎饼馃子. 果 is not correct but usual simplified writing among the people. 馃 means fried.