It seems unlikely to me you'll find another microcontroller with the same pinout, I don't think this one is standard. But maybe there's one.
What I'd do, is use whatever MCU you want that is suitable (i.e. compatible voltage/clocking/IO features) and then either:
1. make a PCB module containing the new MCU, that fits the existing footprint, or
2. dead-bug/point to point wire the new MCU to the old footprint