Peter's route would work. Would be a faff choosing a good route past Axminster.
If you don't want to climb Corfe, you can route via Stoke St Mary, Slough Green, Bickenhall, Broadway. South of the A303, the A358 is okay. Between there and Taunton it's not pleasant.
At Chard you could take the B3120 to Winsham and route through Marshwood Vale to Charmouth—scenic in the best way.