The 51-year-old was convicted and jailed for life in September with a non-parole period of 33 years after being found guilty of murdering her former in-laws, Don and Gail Patterson, 70, and Gail's sister Heather Wilkinson, 66.
A jury found she deliberately served beef Wellingtons laced with death cap mushrooms to her lunch guests in July 2023 at her Leongatha home in regional Victoria.
She was also convicted of the attempted murder of Heather's husband, Ian Wilkinson, 69, who fell seriously ill after eating the meal but survived.
Patterson's lawyers have lodged a formal application to appeal her convictions in the Supreme Court. The grounds for her appeal application were released by the court on Wednesday.
Patterson said there was a "fundamental irregularity" while the jury was sequestered during the trial.
After the jury were sent out for deliberations, it was revealed they had been placed in the same hotel as the police informant and two members of the prosecution team.
"That has fatally undermined the integrity of the verdicts and requires the quashing of the convictions and an order for a re-trial so that justice cannot only be done but be seen to be done," the documents said.
Justice Christopher Beale at the time said the jury had a floor to themselves and were separated from other guests of the hotel.
Patterson further claimed a "substantial miscarriage of justice occurred" because of the prosecution's "unfair and oppressive" cross-examination of her when she gave evidence over several days in the trial.
She said the prosecution's opening and closing arguments also caused a substantial miscarriage of justice because they introduced an implied motive at the end of the trial.
The mushroom cook has also taken issue with evidence that was aired in court.
She said evidence relating to cell towers, death cap mushroom sightings in Loch and Outtrim - posted to the iNaturalist website and from Facebook 'friends' and messages - should not have been permitted because they were not relevant and unfairly prejudiced her.
She also claimed Justice Beale had "erred" when he ruled photos and videos related to mushrooms found on an SD card at her home was inadmissible during the prosecution case.
Patterson has always maintained her innocence and claimed it was a terrible accident.
Crown prosecutors lodged their own appeal in October over Patterson's "manifestly inadequate" sentence.
Justice Beale noted in sentencing Patterson that her offending was the worst category of murder and represented a betrayal of trust towards people she considered family.
But he showed Patterson mercy with the chance of parole, noting she was essentially in solitary confinement for at least 22 hours a day.
Acting Director of Public Prosecutions Diana Piekusis KC said the judge had erred by finding there was a "substantial chance" Patterson would be held in solitary confinement for years to come.
Justice Beale accepted there was no proven motive, but he found Patterson concocted an elaborate story to cover up her offending, including lying about a food dehydrator and having cancer.
