Vanilla beans are long pods of a tropical orchid plant, which is native to Mexico but is also grown, among other places, in the Indian Ocean islands of Madagascar, Comoros and Réunion,

The pods can be cut in half lengthways and the black sticky seeds scraped out on the tip of a knife. These seeds can be added to other ingredients to make biscuits, cakes, custard tarts and other sweet pastry deserts. This is an expensive way to use vanilla, even though the pods can be used a few times before finally being put into containers of sugar to impart the last of their flavour. More commonly, vanilla extract is used. It takes six months to obtain pure vanilla extract from the beans and the extract is 35% alcohol by volume. The flavour is far superior to vanilla essence or flavouring which is derived from phenol.

Why not make a berry and almond traybake, adding vanilla extract to a sponge mixture and spreading two-thirds into the base of a tin. Sprinkle the berries - for example, raspberries or blackberries - over the top and cover with more sponge mixture, then scatter flaked almonds on top. Once baked, cover with glâcé icing that has had a little vanilla extract added.

Fiona Burrell, co-author of Leiths Baking Bible, from Leiths School of Food and Wine