Cult baked goods like the Cronut (a hybrid croissant-doughnut) and townie (a tart-brownie) are all the rage, so it's no surprise that bakeries are protective when it comes to the next big thing.
But Starbucks' latest attempt — the U.K. launch last week of a doughnut-muffin combo called "the duffin" — appears to have plunged the global coffee chain back into controversy, with customers accusing it of copying a small bakery chain that has been selling the product for years.
In a post introducing the product on its website last week, Starbucks said it had come up with a way to combine the two treats.
"Inspired by our muffins, we sat together with our bakers and pondered how you could make a muffin go one step further," the post read. "Step forward the Duffin."
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However, a spokesperson for Bea's of Bloomsbury, a London-based bakery chain with four branches, said it had been selling duffins since 2011.
"They're one of our most popular products and sell out quickly almost every day," Andre Dang told CNBC.
"They've been in our customers' consciousness for some time, which is why so many of them tweeted us to let us know that Starbucks were also selling duffins."
Social media storm
Once it became aware of the situation, Bea's was quick to defend its duffins on Twitter.
But the ensuing social media storm took even Bea's founder, Bea Vo, by surprise. Over the past two days, more than 1,000 tweets including the hashtag #DuffinGate have been sent.
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"Bea has been completely overwhelmed by the support. And it's good publicity — probably better publicity for Bea's than it has been Starbucks," Dang said. "It's nice to see the little guy winning for a change."
Controversial trademark
Bea's insisted that it had no problem with Starbucks selling duffins — but it was angry to discover that Starbucks' supplier, Rich Products, had trademarked the name. This could mean that the small bakery could no longer call its duffin, well, a duffin.
"Bea has never claimed she invented the recipe, nor does she want to own any trademark," Dang added. "But she was concerned that Starbucks would be within their right to ask Bea to stop selling duffins, given Rich Product's trademark."
Starbucks, however, published another post on its website in response to the furor on Tuesday.
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"Since launching, we have discovered there are other duffins out there in the U.K. including at Bea's of Bloomsbury, which is great news for muffin and doughnut fans across the country," the post read.
"Neither Starbucks nor Rich Products has suggested to Bea's of Bloomsbury that they will attempt to stop them selling their own Duffins."
Cronut comparisons
But despite Starbucks' attempts to "set the record straight," duffin-lovers continued to tweet in support of Bea's sweet treat, with some even calling for a boycott of Starbucks.
Bea's responded to the support, posting a 15 percent discount promotion on its website Wednesday to thank "our lovely loyal customers!"
Starbucks has not been drawn into the Twitter debate, sending only one tweet about the duffin on Monday.
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By CNBC's Katrina Bishop. Follow her on Twitter@KatrinaBishop and Google