The young Magpies' three goals were all netted in the second half, with the away side scoring two goals in the space of four minutes, courtesy of Kelland Watts' penalty and Cal Roberts' strike.
Sørensen sealed the victory towards the final stages of the cup tie with his 20th goal of the season, firing a sweet effort into the net to secure United's place in the final of the competition for the first time against a Leeds side containing two full internationals in Northern Ireland's Bailey Peacock-Farrell and Switzerland's Gaetano Berardi.
Sørensen told nufc.co.uk: "It's a decent win and I'm absolutely buzzing for all the lads. We all worked our socks off for the full 90 minutes and I'm very happy to get through to the final. I've said that the most important thing is the team winning but, as a striker, it is my job to get my goals so I'm very happy to score the goal too.
"Leeds had the majority of possession so we had to work very well defensively, which we did and I don't think they caused our team many problems. We worked very well when we had the ball and we took the chances that we were given.
"The two goals were very important. Ben said at half-time to go out in the second half and stay in the game for the first ten to fifteen minutes. When we scored the two goals, we worked well out of possession to restrict them to have many chances in front of goal and make sure they did not come back into the game. That's what we managed to do and closed the game off with the third goal towards the end.
During the first half of the league campaign, Sørensen struck 18 goals before the turn of the new year, resulting in a loan move to Blackpool in January.
Sadly, the striker was unable to break into the Seasiders' squad in a frustrating, short spell with the League One outfit but, after netting against Leeds, Sørensen admitted his delight in re-finding his goalscoring touch and the 19-year-old feels he is capable of reclaiming his eye-catching form after six games without netting for the under-23s.
He added: "I was buzzing to see the ball hit the net. I've not scored for a few games and I've been a bit down with myself. To finally score after so long was a great feeling.
"It's a big weight off my shoulders as I felt I only needed to score one goal to regain the form I had before I went out on loan. I'm delighted and, hopefully, I can kick on from here.
"It would be a massive achievement to win the Premier League Cup as the under-23s have never done that before. It would be great for the boys and we now look forward to the final and see what happens."
