(THE WASHINGTON POST) - No one likes growing old, unless you're Harry Dean Stanton, who apparently emerged from the womb looking like he had been in a bar fight.

But watching McDonald's deal with the onset of old age - the fast-food company we all love/hate is 62 - has been borderline painful. Unlike some hamburger chains, such as In-N-Out and Five Guys, which are content to focus on their core (greasy) strengths, McDonald's has been locked in an epic battle with prevailing trends, investors, nutritionists and itself to remain relevant in a crowded fast-food marketplace.

Over the years, McDonald's has introduced countless items to energise its brand. Some stick. Many die. Even a truncated review of the items reads like the CV of a mastermind with multiple personality disorder.

There was the Filet-O-Fish, which went nationwide in 1965. Three years later, the Big Mac was introduced across the land. But starting in the 1980s, McDonald's went middle-aged crazy. It began dressing up its menu with all manner of accessories to remain attractive: Chicken McNuggets, McPizza and salads. McPasta. McLean Deluxe. McLobster. McFlurry. Yogurt parfait. McGriddles. McCafe. And many, many more.

All the makeovers have given customers whiplash and led to a repeated criticism: McDonald's has an identity crisis, which may or may not have contributed to the chain's prolonged sales slump a couple of years ago.

But McDonald's has recently rebounded, in part because of its Signature Crafted Recipes (SCR) sandwiches, which Mickey D's rolled out earlier this year, along with its frork, that puckish man purse for fries. The chain's switch to fresh meat for most of its quarter-pounders probably did not hurt, either.

Last month, McDonald's expanded its SCR line with a few sriracha-slathered offerings (quarter-pound burger, fried chicken breast, grilled chicken breast) topped with tomato, white cheddar, crispy onions and a mix of baby kale and spinach. It is reportedly the first time McDonald's has ever used kale on a burger, more or less breaking a promise extended in a self-congratulatory, anti-elitist commercial from 2015, which insisted you would never see kale on a Big Mac.

Unlike SCR's sweet-barbecue-bacon and pico-guacamole toppings - which have become fairly commonplace on burgers - the sriracha-and-kale combo smacks of desperation. It reeks of a corporate attempt to capitalise on two of the biggest food trends of the past decade (although far after each has peaked). It is the fast-food equivalent of watching your Dad sport rompers and pledge his undying love for Drake.

I usually avoid desperation, but in this case, I made an exception. I decided to try the sriracha quarter-pound burger at a McDonald's. I was not even sure it was available. I did not spot the burger on the electronic menus that glow over the counter. But the staff assured me they had it.

They should have told me they had a variation on the Sriracha Burger, because this one was missing a couple of key ingredients. The quarter-pound patty had plenty of the Sriracha Mac sauce slathered on the grilled artisan bun (you can select the traditional sesame-seed bun, too), but it had not a single crispy onion nor any baby kale or spinach. Instead, the burger featured softened, almost caramelised, onions and a large, veiny leaf of what looked like romaine. It might have been green leaf lettuce. Either way, it wasn't baby kale, so I was super out of luck if I planned to enjoy the nutritional benefits of this superfood.

Despite its switcheroo, I liked the quarter-pounder jacked up on Sriracha Mac sauce. It was a Big Mac just back from a trip to Thailand - or at least a nearby Thai restaurant - eager to share its spicy new personality.

The next day, I visited a different McDonald's. I wanted to see if another location would serve the burger as originally designed. I also wanted to try the fried chicken version.

This quarter-pounder had all the required ingredients, including one lonely leaf of baby kale to validate whatever warped impulse drives one to seek out superfoods at a chain widely condemned as a contributing source to America's obesity epidemic. Neither the baby greens nor the crispy onions added much to a burger dominated by the flavour and heat of the Sriracha Mac sauce, but their very presence lends Mickey D the air of a gastropub, which is probably half the motivation. Those millennials aren't going to volunteer their arteries to McDonald's without a little kale-bait.

Frankly, I preferred the crispy chicken breast doused with Sriracha Mac sauce. The sauce just aligns better with the flavour and texture of fried chicken. I mean, there's a reason Buffalo mini burgers aren't a thing.

The Sriracha Mac sandwiches are US$5.59 (S$7.60) each and available for a limited time at McDonald's restaurants.