JAB Holdings, the owner of several service brands including Krispy Kreme and Peet's Coffee & Tea, is buying Panera Bread Co. for roughly $7.5 billion.

This should scare cafe chains like Starbucks and Au Bon Pain, Panera's main competitor.

And while their offerings may not be as good as homemade, both Au Bon Pain and Panera serve all the epicurean comforts we often crave: steaming soups, mac and cheese, hot paninis, and more.

But a question arises: Whose food is the better lunch choice?

Panera Bread, with over 2,000 locations worldwide, and its rapidly expanding competitor Au Bon Pain, which has over 300 locations, serve very similar menus.

We put Panera Bread and Au Bon Pain in an extensive head-to-head test to find out who serves the better lunch.

The two fast-casual cafe giants offer very similar menus, so we chose a handful of items we think are classic and hearty cafe fare.

First up: sandwiches. Here are both chains' takes on the hot chicken and mozzarella panini.

Au Bon Pain's Chicken Pomodoro sandwich — with chicken, mozzarella, asiago, tomato spread, and roasted tomatoes — was underwhelming. Despite being made fresh to order, it tastes like prepackaged chicken parm. The ciabatta bread is spongy, and the spreads were lacking flavor.

Panera's version, the Frontega Chicken Panini, is obviously better after the first bite. Everything tastes fresher somehow, despite having nearly the same ingredients —although the addition of chipotle mayonnaise isn't really necessary. One issue, however, is the focaccia bread gets soggy fast.

Onto another simple classic: the turkey club.

The turkey club from Au Bon Pain is a joyous lesson in simplicity: moist yet thin turkey, just enough slices of cheddar, surprisingly crispy bacon, and the perfect amount of tomato slices and greens to add a fresh taste without making the soft white bread soggy. It's delicious. How can bacon, turkey, and cheese go wrong?

Well, this may be how. Panera's version of the turkey club, called the Turkey Bravo, isn't an awful sandwich, but the classic club formula has been strangely tweaked. There are flavors at odds here: The somewhat sweet "signature sauce" doesn't meld well with the mellow smoked Gouda, which gets lost in the bland turkey. The bacon is limp, and the tomato basil bread has a very odd sweetness to it as well. Even the complimentary pickle can't save this sandwich.

Of course, nothing beats a hearty bowl of home-style mac 'n cheese. Who does it best?

Au Bon Pain's mac 'n cheese, simply put, was bland and watery. There just isn't much to it — no heft, no "stick to your ribs" heartiness. It doesn't taste cheesy.

If you want cheesy and hearty, go for Panera's. It's rich and creamy, with a tangy taste of cheddar. It's a little on the salty side, but that's forgivable.

Keeping with the cheesy theme, we move on to another comforting classic: the broccoli-cheddar soup.

Au Bon Pain's take on this rich soup is confusing at best. It tastes salty and peppery, so you would think it's flavorful — but you'd be wrong. It somehow manages to be bland in spite of this. And it's essentially all watery liquid; nothing but tiny little broccoli buds floating about.

By comparison, Panera's is miles ahead. It's thick and cheesy, with large chunks of broccoli and carrots. It's smooth and rich with buttery tones.

Last but not least for soups is the ultimate in winter comfort: the one and only chicken noodle soup.

First, Au Bon Pain. The broth is a tad weak in terms of flavor, but it has a healthy amount of large spiral noodles and vegetables like carrots and onions. The chicken is pretty good too, with sizable chunks. It's a rather impressive fast-casual take on the homey classic.

Panera's is, however, surprisingly disappointing. The broth is very oily, and there's only a smattering of vegetables and chicken throughout. The noodles are odd, stubby, and flat and don't satisfy as much as Au Bon Pain's spirals.

Of course, if you're feeling overwhelmed by all these rich and cozy choices, there are always salads. And what's a more classic and filling choice than a chicken Caesar?

Au Bon Pain's salads are prepackaged, making it super easy for those on-the-go eaters. However, this does not bode well for quality or taste.

The only truly good things about Au Bon Pain's chicken Caesar salad are the lettuce and the croutons. The lettuce looks fresh and tastes crisp, and the croutons are delicious little cubes of savory seasonings, packaged separately to save them from getting soggy. But the chicken is tasteless and gray, and the cheese is scarce.

Panera's chicken Caesar is ordered like anything else there, ostensibly prepared fresh.

The lettuce is a mix of what seems to be iceberg lettuce and romaine — it's a little weak but not bad. The croutons are mixed in, so they become soggy quickly. The chicken is fantastic, however; sliced in very thin strips, it's well seasoned and there are telltale grill marks.

So who takes the fast–casual-cafe crown? Despite not performing perfectly — Au Bon Pain made a fantastic chicken noodle soup and turkey club sandwich — Panera's quality still trumps that of its competitor. Plus, every Panera entrée comes with a free choice of side: bread, fruit, or bags of chips. Not a bad deal, and the food typically tastes great.