L'maki nut

From Memory Alpha, the free Star Trek reference.

L'maki nut was a type of nut indigenous to the Delta Quadrant. When pureed, it made a lustery blue cream that was a popular cake frosting.

Neelix often enjoyed using pureed L'maki nut frosting on his baked goods and pastries while aboard USS Voyager. It was one of Kes' favorite foods. (VOY: "Twisted", "Before and After")

In 2376, while Tuvok temporarily suffered from brain damage, he enjoyed making several desserts, including cakes with L'maki frosting. (VOY: "Riddles")

Later that year for Tuvok's birthday, Captain Janeway replicated a cake with L'maki frosting for him. (VOY: "Fury")