It's baa-ack. KFC's Double Down – the unabashedly greasy sandwich that was nothing short of a marketing dream -- is making a comeback.

You'll of course remember the Double Down. It's the "sandwich" that uses two slabs of fried chicken in place of buns to hold together bacon, cheese and "special sauce."

The Double Down has never shied away from its unhealthy profile; quite the opposite: it's embraced it. With its astonishingly poor nutritional profile, the sandwich earned itself tut-tuts from dieticians and lots of headlines, becoming the stuff of marketing legend.

The last time it arrived, the Double Down boasted 30 grams of fat, 1,740 milligrams of sodium, 540 calories, no fibre and precious few vitamins.

This time, the Double Down is going to be a smidge healthier.

KFC Canada says its "chefs" (you read that right) have trimmed the sodium slightly -- by 10 per cent.

By our calculations, that works out to 1,566 mg of sodium – still more than the maximum that most health experts say an adult should take in, in an entire day. But KFC says that's what customers want.

"KFC fans told us they loved Double Down and they wanted it back in all its delicious glory – and they also asked us to keep all the indulgent flavour and reduce the sodium a little," explained David Vivenes, senior marketing director of Yum! Restaurants Canada, which owns the KFC brand in Canada, in a press release.

Once again, the Double Down will be offered on "a special, limited time" basis. It will begin appearing at KFC restaurants across Canada on June 1st and will remain available "while supplies last."

(We suspect that's code for "as long as it's still making headlines," but chances are good the sandwich will be available for most of the summer.)

The first time the Double Down arrived in Canada -- for a mere five weeks last fall -- more than 1 million were sold, earning the sandwich the honour of KFC Canada's best-selling new item ever.

This time, to get customers talking, 15 restaurants across the country will offer Double Downs for one day only, May 27, from noon to 2pm only.

Vivenes advises Double Down enthusiasts to arrive early to get their hands on one before supplies run out.