Starbucks Hawaii customers who’ve missed their favorite oatcake, a top-seller made by the Honolulu Baking Co., once among the snacks available at the ubiquitous coffee chain, can now get the nutritious treat at Costco.

Local baker Yuri McPhail started making the oatcake 23 years ago when the nation’s largest coffee chain first opened in Hawaii in December 1996, and it became the so popular she was churning out a thousand a day — “it was crazy!” McPhail said athletes in particular liked the dense, chewy cake because it was high in fiber, low in fat, and it provided them energy for hours as a breakfast item or afternoon snack.

“And I think you just got addicted to them. You either loved them or didn’t like them at all!” she said.

The oatcake, which contains rolled oats, whole wheat flour, blueberries and cranberries, was originally 5 ounces and equivalent to two servings with a hefty 500 calories; each sold for about $3. McPhail’s newly released oatcake for Costco is 3 ounces, 280 calories, and sells in a six-pack for $8.29, which breaks down to $1.38 each before tax. Families will find the price more budget-friendly, and the six-pack can be stored in the freezer and defrosted individually as needed, she added.

Her cakes were still extremely popular when Starbucks revamped its vendor practices and discontinued selling them.

“I’ve been fielding calls daily from irate oatcake fiends,” she said. They contacted her wanting to know where to find her cakes.

McPhail said she was “just lucky” creating the recipe that launched a thousand fans, making it initially for friends. It was her husband Dean McPhail, then president of Coffee Partners, who got her to bake the oatcakes when his former company opened the first Starbucks in Hawaii at Kahala Mall.

It became the chain’s top-selling baked item in the nation, though it was only made here, according to a 2005 “By Request” column.

She said, “I’ve had a wonderful partnership with them, but now I have my Costco family!”

The cakes, which started selling this month on Oahu, are available at Costco’s Iwilei, Hawaii Kai and Waipio locations, and will be sold on the neighbor islands in the next few weeks.