The 49-year-old woman was cutting potatoes for French fries at her home in Berlin's Charlottenburg district when the cross-shaped cavity inside one of the spuds stopped her cold.
"There was a strange sort of crackling sound like pressure was being released. When she opened it she found that - two perfect crosses," her British husband told The Local. The family has asked not to be named.
The woman, a Muslim, called her family and neighbours to witness what local newspaper Berliner Morgenpost is calling "the miracle of Berlin-Charlottenburg."
"Everyone was deeply stirred," she told the paper. "Some of them even began to weep and to pray."
News about the unusual potato preserved in a bowl of water in the family's kitchen spread quickly around her neighbourhood. She quickly found a constant stream of pilgrims on her doorstep.
"They all wanted to see the holy potato," her 21-year-old son told the newspaper. "One woman even drank some of the water around it. Another wanted my mother to bring the potato to her apartment for good luck."
Gesche Hohlstein, a biologist and spokeswoman for the Berlin Botanical Garden, said the hole in the centre of the potato could have been caused by fungus or bacteria - and said it didn't resemble a cross to her.
But Catholicism, at least, is open to the idea of holy symbols being present in everyday life, Markus Thurau, a Catholic theologian at the Free University of Berlin, told Berliner Morgenpost.
"There are continuous phenomena like this," Thurau said. "In principle the Catholic church is open to miracles like this, but of course it could always just be a coincidence."
The woman said she views the potato as a sign - whether or not there is a natural explanation for the cross symbol.
"Miracles play a huge role in Islam as well, and I believe in them," she said, adding that she had the potato shrink-wrapped at her corner butcher shop to preserve it.
"This way it will stay good a few weeks longer," she said. "And then we'll see."
The couple's son has set up a blog dedicated to the potato, which her husband said the family may sell on eBay.
"My wife thinks she's been chosen, a little bit. I personally think it's just one of life's strange things that happen," he said.
"She feels it's strange that among two million Christians, a Muslim lady found it. She thinks, 'Well, I guess it's a little bit miraculous and a little bit nice.'"