Testers answer the ultimate culinary question: Which is the UK's best caterpillar cake?
Any party you've been to over the last 10 years is likely to have featured a caterpillar cake.
Now, researchers have answered the ultimate question: which is the best?
Marks and Spencer's Colin the caterpillar and Aldi's Cuthbert the caterpillar might have been the cakes in the headlines in recent years, after M&S accused Aldi of copying its design.
But a blind taste test by consumer watchdog Which? has found that the Co-op's Charlie the caterpillar is the best cake - edging out all competitors with its "ultimate combination" of chocolate, sponge and buttercream.
The Co-op's Charlie, at a cost of £8 for 660g, was given a 72% score and a coveted "best buy" recommendation by the testers.
Which? said the cake had "wowed" tasters, with head of home products and services Natalie Hitchins saying: "As well as being budget-friendly, Co-op's Charlie the caterpillar had a rich chocolate flavour and plentiful amount of buttercream".
Marks & Spencer's Colin was placed second, given 71% for its "superior sponge and delicious chocolatey flavour".
It was also given a "best buy" recommendation, although at £8.50 for 625g, it is the pricier of the top two options.
M&S took Aldi to court in 2021 over a long-running dispute in which it accused the budget rival of copying Colin for its own Cuthbert. The two agreed a settlement a year later.
Tying for third place were Morris the caterpillar from Morrisons and Wiggles the caterpillar cake from Sainsbury's.
Morris (£7.50 for 624g) won 70% but testers found the sponge "a little disappointing" while Wiggles (£7.50 for 627g) lacked "much-needed moistness" and some tasters thought the chocolate shell was too thin.
Waitrose's effort - Cecil the caterpillar (£8.50 for 720g) - scored 69%, with testers enjoying the chocolate flavour, sweetness and thickness of the chocolate shell, but also feeling there was too much sponge compared with buttercream.
Aldi's Cuthbert, the cheapest option at £5.49 for 625g, was given 68%, with some tasters finding the sponge too dry, although Which? said it was not a bad choice for a budget birthday cake.
Tying with Aldi's score was Tesco's Slinky the Caterpillar Cake (£7.50 for 648g), criticised for being "too dry" and lacking buttercream.
Asda's Letty (£7.50 for 615g) came last with a score of 67%, with tasters concerned about its weak chocolate flavour and dry sponge.
Nicole Tallant, Co-op's head of delicious food, said: "We're thrilled that Which? has settled the big caterpillar cake debate and named Co-op as being the best tasting on the high street for the second time.
"We're passionate about making delicious products and we know our Co-op members and customers love Charlie so it's great to get this recognition."
