Edinburgh-er here - skon for the cake thing, skoon for the town. Skown never.
Normally when you say 'skoon' you're referring to the 'stone of scone', our big lump of magical red sandstone, which is obviously completely unlike any other bit of rock you might find on your travels. Used to be what the kings/queens of Scotland were crowned upon until the English stole it for theirs to sit on; if you say it that way, we'll have to assume you're interested in a debate about the role and future of the monarchy and will engage you.