The midfielder helped Stevie Smith’s side to Old Firm glory by tucking away the decisive spot-kick in the shootout after it ended 1-1 after 90 minutes.
The talented playmaker watched keeper Rydnn McGuire save Daniel Cummings’ spot-kick with Paul Nsio missing for the Light Blues.
In sudden death, McCallion tucked his effort away before Lewis Dobbie fired wide to give Rangers the victory.
Speaking to RangersTV, he said: “Rydnn helped us out with his save and the boys who took penalties took them well and it is a good way to win the game.
“I was nervous with my penalty, but I was confident as well. You just have to step up and score, and I did that.
“We conceded the goal at the end of the first half and Stevie told us to stick together and go for it as we had 45 minutes to win the game and we did that.
“You want to win silverware at Rangers and that is what we should be doing at this club. I am delighted to win it.”
The 16-year-old has been part of first-team squads in recent weeks under head coach Barry Ferguson.
He was part of the team that travelled to Spain to take on Athletic Club in the Europa League quarter-final clash earlier this month.
First-team member Nana Kasanwirjo, on his first outing since November, opened the scoring for the Gers on the night and McCallion says he is loving working with the top team every day.
He added: “Nana has a lot of experience and he spoke to us during the game and it was good to have him behind us.
“I have been working with the first-team these past few weeks and I have been in a few squads, so I am really enjoying it.
“It has been a good experience being amongst the boys and the manager as well.”
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