Suggestions for places to see between la spezia to pavia

My experience with the coastal road, from many years ago, is that much of it is in tunnels, and not scenic at all. There are some nice coastal towns along there, but won’t you already have spent time at the coast?

Going the inland route, it looks like Parma is just about halfway and would make for a nice stop for a break.

Thank you I had no idea the coastal road would be tunnels. I’ll look into Parma.

The inland route is very pretty as it passes through the Apuan Appenines and generally follows the path of the Via Francigena, the pilgrim route between Rome and Canterbury. Smaller cities well worth a stop on the way are Pontremoli, Fontanellato, and Castell'Arquarto. Pavia is an excellent choice, it's deep in history and has a wonderful atmosphere - you'll wish you had more time there. Outside of Pavia, don't miss the fantastic Certosa of Pavia.

Definitely go inland from La Spezia towards Parma. Coming down from the Cisa tunnel towards Parma for the first twenty minutes requires attention lots of bends so respect the speed limits and you'll be fine. Otherwise that route is an easy drive with vastly less traffic then heading up towards Genoa and inland from there. The only doubt is roadworks because they're replacing a bridge going up - check Google maps for travel times a few hours before departure.
It may be too near to your departure point (stop for breakfast or coffee?) but Bagnone is a hidden gem
https://slowtravelitalyspain.blogspot.com/2020/03/massa-carrara-in-may-bagnone.html?m=1

Thank you both. Good ideas I’ll check it out. We are going in September, hope by then the roadworks will be finished. Does anyone know if Waze works in that area?

Waze works and it is popular in Italy so the traffic camera postings are accurate. Google Maps also works well and I suggest you download maps for off-line use for the areas you're visiting in case of breaks in cell reception.

Thanks. Good idea.