The Dutchman put the Royal Blues in command within half an hour before wasting the chance to wrap things up from the penalty spot.
It did not prove to be a costly miss, though, as former Hoffenheim forward Chinedu Obasi made it three before Huntelaar completed the scoring and snatched the matchball.
In a game involving a side with the third strongest attack and the third weakest defence, goals were always likely.
And it was Hoffenheim who took a step closer to having the worst defence in the league rather than the best attack as they fell behind in the sixth minute.
Joel Matip squared the ball for Huntelaar after Hoffenheim failed to clear their lines and the Dutchman stroked the ball past Koen Casteels, leaving the Hoffenheim goalkeeper no chance.
Hoffenheim nearly levelled immediately with Kevin Volland's shot saved by Ralf Fahrmann before the ball fell to Anthony Modeste, who failed to find the target from a tight angle.
Schalke doubled their lead in the 29th minute when Julian Draxler played a perfect pass for Huntelaar, who let rip from the edge of the penalty area to beat Casteels once again.
Only a minute later, Huntelaar had the chance to make it three from the penalty spot, but after using power and accuracy for his two goals from open play, he cheekily tried to scoop the ball past Casteels, who embarrassed the Dutchman by making an easy save.
Hoffenheim made a better start to the second half, but within 10 minutes they were in an unforgiving position at three goals down.
Obasi, facing his former club, was served by Kevin-Prince Boateng and his powerful effort left Casteels with no chance.
From then on in, it was a case of limiting the damage for Hoffenheim and they succeeded up until the 79th minute, when Draxler beat Roberto Firmino before crossing for Huntelaar to complete his hat-trick from close range.