The 19-year-old, who scored three goals in seven appearances during a recent loan spell with the Pilgrims, has put pen-to-paper on a contract for the upcoming National League North season which will officially come into force when his Bradford City deal expires at the end of June.
Clare netted against Curzon Ashton, Ashton United and Hereford FC during his initial loan spell with United.
Reflecting on Clare's arrival, United manager Craig Elliott told bufc.co.uk: "I am pleased to get Tom signed up as there was a lot of interest from other teams.
"He ended the season very well and it was clear to see that at 19 he has a lot of potential and will only get better.
"There are not many young target men available with a good touch and a change of pace and he will score goals too.
"I am delighted to have him onboard."