Not sure whether such a language already exists though the challenge is to establish a Gallo-Iberian language, basically a language that can be very loosely defined as Frespañol in a similar manner to how Gallo-Italic languages can be described as halfway between French and Italian due to differing evolution and diffusion of various linguistic tendencies.
https://en.wikipedia.org/wiki/Frespañol
https://en.wikipedia.org/wiki/Frespañol