It was an old family recipe.

California police are investigating reports that a high school kid baked the ashes of one of their grandparents into sugar cookies and passed them out to classmates.

As many as nine kids at the DaVinci Charter Academy in Davis, California, may have noshed on the cannibal cookies, CBS Sacramento reported.

“This is a weird one,” Davis police Lt. Paul Doroshov told the outlet. “I have not heard of anyone getting sick or anybody being harmed as far as physically, physiologically by this.”

Two students are believed to have cooked up the morbid plot.

The Davis Joint Union School District declined to provide details about the investigation.

“This case has been particularly challenging and we have responded appropriately and in the most respectful and dignified way possible,” the district said in a statement.

Investigators got the bizarre tip from students and have not yet been able to test the cookies, CBS reported.