I actually had to do this a few months ago for a client. They hired me to backing tracks and sent me the songs on cassette
. A bit of a pain in the neck but the solution for me was just to make a stereo recording from the headphone jack of an old cd/cassette player. I used a 1/8" cable from the headphone jack split into two 1/4" jacks going into my interface. Didn't necessarily sound the best but then again they weren't the best recordings either. Assuming your recordings are relatively clear and not overpowered by tape hiss this method might be fine. Alittle noise reduction or gating might help remove some (but not much) tape hiss but a bad sounding tape however will just be that. maybe thats where baking might come into play.