After testing out the product in Nashville earlier this year, the fast food chain announced a nationwide roll-out in the US of the sweet and savoury sundae made with vanilla soft serve, topped with chocolate fudge, caramel, bacon crumbles and garnished with a thick-cut bacon slice garnish.

It's a play taken straight out of family-style restaurant chain Denny's, which enjoyed wild success last year with its Maple Bacon Sundae, a product that became a viral hit and conversation starter around the world.

Meanwhile, as predicted by trendspotters and food consultants last year, Burger King is tapping into the growing appetite for Southern fare and regional flavours by launching a summer menu of Texas or Carolina bbq and Memphis-pulled pork sandwiches.

Similarly, sides are going upscale down home as well, with the launch of sweet potato fries.

Last fall, market research group Packaged Facts forecast that the strong, robust, punchy flavours of Southern-style cooking would be popular this year, while San Francisco-based trendspotter Andrew Freeman & Co. declared 2012 the year of the potato with more restaurants gussying up the humble side.

The new menu revamp comes as rival Wendy's embarked on a complete overhaul last year, reformulating its original 42-year-old burger recipe and redesigning its restaurants. The strategy proved successful as the Ohio-based chain dethroned Burger King in sales volume for the first time last year since it was founded in 1969.