After going behind in the game, the 16-year-old drew the young Gers back level at the end of the first half before making it a double in the second-half.
The result saw Rangers progress to the third round of the UEFA Youth League, with a 4-1 aggregate victory.
Speaking to RangersTV after the game, he said: “It was a good performance from the boys, a good team performance and individual performance, I am a bit frustrated that I didn’t get the hat-trick but a few goals you can’t really complain.
“I am always delighted to get the goals that is part of the job but it is more about getting through to the next round.
“It was a great bit of positivity and creativity from Kai to flick me in and I took my opportunity well and then the second one Nathan Patterson his great cross into me and I managed to put it away.”
Young-Coombes says confidence is high in the squad at the moment after a string of positive results and performances.
He added: “I think again we go into games knowing that we are the better side, that we can play that we are going to win so the boys, every position is a standout player and I couldn’t swap anybody out of the team because everyone is playing in fine form.