Jones and Speirs also wrote and starred in Stella, a series about life in a fictional valleys town which ran between 2012 and 2017.
Better Later follows retired teacher Clive, played by Speirs, and environmental health officer Shelley Anne, played by Jones.
Clive, 60, is adjusting to life after being widowed, while 55-year-old Shelley Anne is going through a bitter divorce.
Jones said: “In a funny way this show has been 35 years in the making, which is when I first met Steve.
“It’s not that we’re slow writers, it’s just that we’ve been up to other things. It’s fantastic to be back in front of the camera with him again.”
Speirs added: “Our first time acting together for quite a long time, Ruth makes me laugh more than anyone and I’m a terrible giggler.
“This could be a long shoot.”