A 2-0 win at Bodo/Glimt in Thursday night's semifinal second-leg sees Spurs reach the final 5-1 on aggregate.
At the final whistle, Kulusevski said: "It felt great – everything felt great coming here to Norway and playing against a good team and reaching the final. It was a great day and I'm very happy. And now it's all focused on the final.
"The coach was very clear with what he wanted from me and from from the other guys, so I just did my job and played strong. I knew that it was important to do everything right today and be very disciplined, and that got us the win."
Meanwhile, defender Van de Ven also stated: "It's an unbelievable feeling. What can I say? We've had a tough season but we're one game away from winning silverware.
"We showed some character and mentality. They didn't create any chances and then we scored two goals and kept a clean sheet."