The on-loan Wolves striker opened the scoring for Hibs 15 minutes in before sending the Edinburgh club through to the final four with two goals in the final eight minutes, including an 89th minute penalty.
Griffiths has now scored a total of 22 goals for Hibs this campaign with the treble adding to his 19 in the league and he was thrilled to be on the verge of another cup final after last seasonâ€™s defeat to arch rivals Hearts at Hampden.
"It is not just me who is the Hibs fan, Paul Hanlon is as well and we know what it means to the Hibs fans to win the cup," he said.
"We have the chance to rectify that now. If we get through the semi-final then hopefully we can go one step further.
"The gaffer spoke to us after the game (against Killie) on Wednesday to tell us how important this game was going to be and to get back to Hampden.
"Last year we said, 'is it going to be this year and what better way to do it than against Hearts' and we got absolutely humiliated.
"We embarrassed ourselves and most of all the club last season and we just have to rectify that.
"It was probably the biggest derby there will probably ever be and it was a shambles really.
"Fair play to Hearts they won it, they played better than us on the day. But we are not going to talk about the final just yet, we have important league games coming up starting against Hearts next week."