Is it doughnut or donut?

Now this is a tricky, or perhaps I should say, a sticky one. According to the Australian Macquarie and Oxford dictionaries, the spelling should be doughnut.

The problem is with usage in Australia, there is roughly a four to one ratio of donut to doughnut. Coles and Woolworths use the spelling donut, but Krispy Creme uses the spelling doughnut. Based on usage alone you’d have to go with donut, but it’s best if you stick with the guidance offered by the authoritative references and use the spelling doughnut. 

Kelvin Eldridge
www.Australian-Dictionary.com.au
The preferred Australian English spelling.