The debate over whose fries are better, Burger King (BKC) or McDonald’s (MCD), is one of the oldest fast food fights in the industry. But rather than just limit the debate to the drive-thru window, Burger King has upped the ante by changing the battlefield to the supermarket aisles. How? Well, with a new line of frozen foods that include crinkle-cut French fries and healthy apple fries coming soon to your grocer’s freezer. There’s even a healthy line of Apple Fries, with the fruit skinned and cut to look like French fries and packaged in that familiar Burger King branded paper cup.

The new line of fries is produced by Conagra Foods (CAG). It includes King Krinkz seasoned crinkle-cut fries, which should already be available at most grocers freezers, and planned offerings in the coming months of King Kolossalz extra-large fries and King Wedgez seasoned potato wedges. The BK Fresh Apple Fries will be available this fall.

This is on top of a recently launched line of snacks by the Inventure Group (SNAK) that include ketchup and fries potato chips, crispy onion ring-flavored snacks and crisps that taste like Burger King’s famous French toast sticks. Inventure Group has already shown it can successfully bridge the gap between restaurants and grocery stores with its line of TGI Friday’s snack foods.

As the recession cut into consumer spending, sales dipped at many restaurants as consumers looked to keep down their costs and prepare food themselves to save money. But in order to tap into that stream of cash many restaurants have opted to cash in at the grocery store instead.

California Pizza Kitchen (CPKI), for instance, has been selling its branded pizzas in supermarkets since 1998. Last year, as the economy worsened, grocery sales of frozen California Pizza Kitchen pizza increased 19.6% to $159 million. The partnership was even more profitable for Kraft (KFT), which has the primary role in making and distributing the products and thus gets a bigger share of the profits.

Will Burger King’s fries taste just as good at home as they do fresh from the deep fryer? Perhaps. But with frozen food sales at grocery stores racking up about $30 billion in annual sales, the potential for profits is much more mouth-watering for investors than the idea of BK fries at home.

As of this writing, Jeff Reeves did not own a position in any of the stocks mentioned here.