Crookes, 20 made his Bulls debut in 2009 and has made eight appearances for the club whilst Crossley, 21, played in seven games last season after being outstanding on the England Academy tour to Australia in 2009.
Danny Addy, who is 19, was brought in to the first team squad at the start of the year, shortly after signing a two year contract and figured in twelve games for the club last season, scoring two tries and kicking two goals.
Bulls Acting Head Coach Lee St Hilaire said of the three signings: “We are delighted that all three players have signed new two year contracts with the club. Jason and Steve have been in the First Team environment for a few years and Danny was brought into it at the start of last season. They are all developing well and we are confident of them improving even further during the length of their contracts. It’s important that we keep our most promising players and reward them for the progress they are making.”