Launched last year, shoppers loved M&S' Best Ever Burger.
Over the course of barbecue season the high street chain sold an incredible 4 million to hungry customers - making them the store's most popular ever burger - and it's not hard to see why.
Experts at M&S spent a year working obsessively to get the flavour right - and settled on a patty that's made from specially selected cuts of British beef with an added hint of bone marrow "for that extra special flavour".
In the Mirror's taste test, they excelled - scoring a rare 10 out of 10.
This is how we described them at the time: "Cooked to a perfect even brown and stayed the same, chunky size so fit burger buns to perfection. Tasted of good quality steak with just the right hint of seasoning.
"They don’t need any relishes or extras as they are succulent and delicious on their own. One of the most expensive but worth shelling out for.
"How a burger should be."
So what do you do next if you have a best-selling, excellently reviewed product?
M&S' answer was to add cheese - but keep the price the same.
Describing the new offering as a "fully loaded version" of the Best Ever Burger - the new product comes with a mix of cheese, gherkin, mustard and tomato sauce ready to go on top.
M&S' meat product developer Sarah Loxton explained: “We wanted to go even bigger and better this year so have ‘pimped’ the burger with a cheesy melt which gives a gooey, golden topping.
"It’s not just any cheese topping, we’ve added gherkins, mustard and tomato sauce for a real flavour punch that’ll have everyone shouting that we have the best ever burger.”
Both the classic and the fully loaded version of the burger cost £3.50 for a two pack. Although you can also get 8 for £16 online if you're planning a bigger event - or just want to stock up.
And if that seems a bit much, the good news for people seeking a premium burger for a bit less it that Aldi's just launched it's own Specially Selected Perfect Burger - on sale for £2.49 for a two-pack.
What makes Aldi's version so special?
"Aldi’s chefs have spent over a year perfecting the recipe," the German retailer explained.
The burgers are made using the best prime cuts of British beef, with a dash of natural bone marrow "for an added depth of flavour" as well as roasted onion and porcini mushroom seasoning to add to the taste even more.
And if you're feeling fancy, you can add Aldi’s Specially Selected Brioche Burger Bun (79p for four) and you have a gourmet burger experience for less than £1.50 a serving.
Although you'll have to add your own cheese.
