Each team cooked five courses for a panel of judges in front of their family and friends.
The bubbly blondes' winning menu consisted of champagne crayfish, followed by paua tortellini, beef cheeks with horseradish mash, venison tenderloin with fennel and watercress, and a saffron-poached pear with dark chocolate mousse for dessert.
The judges praised the two aspiring chefs for their ability to bring simplicity to perfection and their play on flavours.
On judge even said it "brought my taste buds to life".
The pair had never cooked a five course meal before and were humbled to make it to the final.
"Never in my wildest dreams did I think I would be in the grand final of My Kitchen Rules," Stella said.
Jess admitted it was difficult to come into the competition as gatecrashers.
"We've learned so much, done some crazy challenges, met some amazing people. Coming in as the Gatecrashers was hard but I'm really glad we did it as well," she said.
The aspiring chefs were now deciding on what steps to take next.
"There are so many possibilities now," Stella said.
"It's going to change our lives," Jess added.
"We'll finally be able to travel the world and taste all the food we've haven't been able to yet, that's our ultimate dream."
Runners-up William and Zoe said while the competition was challenging, it was a great experience.
"Being on MKR has been one of the most challenging, yet rewarding experiences I have ever had," said Zoe.
"Despite falling at the final hurdle, I am immensely proud of what Will and I have achieved. We've come out the other side as much better cooks and with some wonderful friends. Huge congratulations to Jess and Stella who were such incredible, deserving winners - you girls have done yourselves, your families and Wellington proud!"
