Binangkal or Bangkal

Hi all. This morning, we ate some 'binangkal' and someone asked what the meaning of the word was. I said I had read that it came from the turtle's egg and how it was buried in the sand. I am sure that I heard or read that somewhere before, that a turtle burying its egg is referred to as bangkal, and that the appearance of the cake, binangkal, is supposed to resemble a turltle's egg coated with sand. However, when I tried to look it up, all I can find anywhere is that Bangkal is the name of a tree. Have I imagined this meaning of bangkal / binangkal, or does someone else know of its use in this sense? Thanks daan. Brian