Unfortunately, I wasn't able to find any more Dagbani language learning videos than the ones that Allison already links in her blog post (and it looks like you watched in class this week).
UCLA phonetics lab has an audio archive entry for Dagbani, but it is geared toward documenting the language not teaching a non-speaker.
I did find print resources that might be helpful... with the hefty caveat that since Dagbani, like many sub-saharan African languages, is tonal you really need to physically hear the spoken pronunciations to make progress with the language. In any case, here they are:
Sorry I wasn't able to locate more!