It’s not fully the type of answer you want, but there is an Italian book called “the revolution of the moon” that is 90% written in dialect. The first pages are mostly Italian with some words in Sicilian dialect, then the dialect part gets more and more prevalent until it’s only dialect.

It’s not exactly what you mean in the sense that the Sicilian dialect really exists and that the book clearly exploits the similarities between the dialect and Italian for the reader to understand.