The couple have been together since 2006 and have six children.
They are parents to Hannah (5) and three-year-old Mahy, and Baz is stepfather to Tanja's four children from a previous relationship, Charlotte (18), Harry (17), Jake (13) and Amelia (11).
When asked if wedding bells were on the horizon, Baz revealed the pair are set to get hitched.
"Yeah we're engaged, I asked her earlier this year, nowhere special, just in Dublin," he told the Herald.
Speaking previously, Baz said Tanja was "very different" to any woman he had met before.
"She was very strong. She didn't care about television. She's a brilliant girl, really cool and we just get on great," he added.
Baz is currently promoting the second season of the hit show 50 Ways To Kill Your Mammy.
While he doesn't mind sharing the screen with his mother, he would never do a reality show with the rest of his family. However, his daughter Hannah does appear in the new season of 50 Ways... which starts on Sky One on September 1 at 9pm.
"My mum Nancy was training as an elf with Santa in Lapland and she kept going on that she would love to bring her granddaughters out there so we flew Hannah out," Baz explained.
His 72-year-old mum said seeing her five-year-old granddaughter running through the snow towards her "nearly killed her".
"I suddenly saw this little figure running along and someone calling Nana and next thing she was beside me - now that was great," Nancy said. "Now Hannah thinks I work for Santa," Baz laughed.
The format for the show has been sold to more than 100 different countries around the world and Baz's production company, Brown Bread Films, has reportedly pocketed €5m as a result.
However, despite their continued success, neither Baz or Nancy has splashed out on anything fancy - bar an engagement ring.
"I go to my usual place, the Canary Islands.
"I love Gran Canaria and I have some friends over there and that's for me and that's all I want," Nancy said.