Tonka Bean.

Tonka bean is the seed of the cumaru tree, native to Venezuela and Brazil. Its character comes from coumarin — the same molecule that gives cut hay and new-mown grass their sweet smell. Tonka is hay, almond, vanilla and warm tobacco rolled into one.

It is the great softener of gourmands, the warm pillow under amber, and the secret reason fougères smell so comforting.