The 1842 Census of Upper Canada, which includes a head of household for Toronto is now online at familysearch.org
John Askin, freeholder (owns his property) is listed in St Andrews ward, on Newgate St The household had 2 persons born in Ireland, 2 born in Canada, a boy and a girl age between 5 and 14. The immigrant has been 14 years in Canada and all 4 are Presbyterian. You might want to check the records of Knox Church, which have been transcribed by OGS Toronto.
1842 census with John Askin is at https://familysearch.org/pal:/MM9.3.1/TH-1-11352-4538-99?cc=...
If John Askin owned his house in Toronto, there might be information in the land records and possibly a will.