I was told many years by a gourmet baker that flan or creme caramel is French in origin going back to the 1800s but now it is standard dessert fare throughout Latin America and like other Latin platters like tamales and chicken n rice etc etc it varies nation to nation and even regionaly within larger countries.
My favorite style is Cuban flan and in particular Cuban style coconut flan, my least favorite is Mexican style flan. Once while vacationing in Miami Beach I had some home made Cuban style mango flan, quite unique. I also like New Orleans' creme boulee- a "cousin" of flan. While visiting Barcelona-Spain I had a Catalan province version of flan they call crema catalan-Catalan cream.
The last few years I have had to drastically reduce my intake of my favorite dessert flan and limit it to 2-3 servings a year, due to cholesterol concerns but for decades previous I more than eaten my share of dozens of varieties of flan, much more than the average bear.
"Some folks eat to live, others live to eat"