Biodiversity Cake

This ‘Biodiversity Cake’ includes ingredients from as many as 16 different plant species from all parts of the world. When we enjoy a slice of rich fruit cake, we should remember how the Plant Kingdom provides us with a remarkable range of products, which we can combine in ingenious ways to produce delicious foods!



350g / 12oz                     Self-raising Flour
2 tsp                                Mixed Spice
1 tsp                                Ground Nutmeg
1 tsp                                Cinnamon
125g / 4½oz                    Ground Almonds
450g / 1lb                        Currants
450g / 1lb                        Raisins
450g / 1lb                        Sultanas
225g / 8oz                       Glacé Cherries, chopped
125g / 4½oz                    Blanched almonds, chopped
225g / 8oz                       Mixed peel
1                                      Lemon, rind and juice of
1 tsp                                Molasses or black treacle
350g / 12oz / 3 sticks    Butter
300g / 10½oz                 Dark brown sugar
8-9                                   Large eggs, beaten
8tbsp (or more!)          Irish whiskey


Pre-heat the oven to 300ºF.  Line a 10 in round cake tin with a double layer of greaseproof paper, Brush the paper with melted butter.  Tie a double layer of brown paper around the outside of the tin. Sift all the dry ingredients into a large mixing bowl. Mix in the fruit, nuts and peel.  In a separate bowl, cream the butter, sugar and grated lemon rind and beat until fluffy. Beat in the 8 eggs, one at a time.  Add an extra one if you think the mixture needs it.  Stir the egg and butter mixture into the flour and fruit mixture, and add in the lemon juice.  Add in 4 tbsp of the whiskey and the molasses.  The mixture should be soft and moist.  Spoon the cake mixture into the prepared tin.  Level the top and bake the cake in the pre-heated oven for 1½ hours. Then reduce the heat to 250ºF and bake for another 3 to 3½ hours.  The cake is cooked when it starts to shrink from the sides.  Check if a skewer inserted into the middle comes out clean too.  Cover the cake with brown paper during the last few hours to prevent it burning.  Remove from the oven and leave to cool a bit before turning out onto a rack.  When it is completely cool, wrap in aluminum foil.  After about a week make a few holes in it with a skewer and pour over the whiskey.  Re-wrap.  The cake can be iced with almond paste and icing for the Holidays too.

  • Flour (Triticum aestivum, wheat)
  • Mixed spice – Mixed spice typically contains cinnamon (or cassia), nutmeg and allspice. Mixed spice often includes:
    • Cloves  – Cloves are the aromatic dried flower buds of a tree, Syzygium aromaticum (Myrtaceae).  Cloves are native to the Molucca islands in Indonesia;
    • Ginger – ginger root is the rhizome of the plant Zingiber officinale (Zingiberaceae).  Its origins are in southern Asia;
    • Coriander – Coriandrum sativum (Apiaceae) is native to regions from southern Europe and North Africa to southwestern Asia;
    • Caraway – Carum carvi (Apiaceae) is native to western Asia, Europe and Northern Africa;
    • Cayenne pepper – Cayenne pepper is a red, hot chili pepper named for the city of Cayenne in French Guiana.  It is a cultivated form of Capsicum annuum (Solanaceae), related to bell peppers and jalapeños).  Peppers were originally domesticated in Mexico and Peru.
  • Nutmeg – Nutmeg comes from a tree of several species of trees in genus Myristica. The most important commercial species is Myristica fragrans, native to the Banda Islands in the Moluccas (or Spice Islands) of Indonesia. The nutmeg tree is important for two spices derived from the fruit: nutmeg and mace.
  • Cinnamon –     Cinnamon is a spice obtained from the inner bark of several trees from the genus Cinnamomum (Lauraceae). Cinnamomum verum (“real” Cinnamon) is native only to the island of Sri Lanka and to Southern India,  but is now widespread in South East Asia. Cinnamumum aromaticum, a milder tasting species, is more frequently sold, and originated in China.
  • Almonds – The almond (Prunus dulcis) is a tree native to the Middle East and South Asia. “Almond” is also the name of the edible and widely cultivated seed of this tree.
  • Currants – Currants are dried small Black Corinth grape (Vitis vinifera).  Currants may also be Ribes, dried Black currants (Ribes nigrum).
  • Raisins – Raisins are dried large black grapes.
  • Sultanas – Sultanas are large dried white grapes
  • Cherries – Fruits of Prunus serotiona
  • Mixed peel – Mixed peel is generally derived from lemons, oranges or grapefruits.
    • orange, Citrus × ​sinensis is one of the most commonly grown fruits in the world.  It is of ancient hybrid origin.
    • grapefruits Citrus × paradisi) is a subtropical citrus tree, an 18th-century hybrid first bred in Barbados in the Caribbean Islands.
  • Lemon – Citrus × limon is a small evergreen tree native to Asia.
  • Molasses black or black treacle Molasses is a thick sticky by-product of the process of making sugar from sugarcane (Saccharum species) (Poaceae). They are grasses, originally native to south Asia, and now one of the most widely grown tropical crops. In the Midwest and Southern US, molasses is often also made from Millet (Sorghum bicolor).
  • Dark brown sugar – From sugarcane.
  • Irish whiskey – Made from fermented barley mash (Hordeum vulgare) (Poaceae)

“The botany of a fruitcake is as rich, complex and intriguing as its taste. The latter can be achieved only by the masterful blending of the odors, flavors, and textures of a wide and extravagant assemblage of ‘botanicals’ whose habitats range the world, from the tropical Spice Islands to the temperate Corn Belt.”

From the Archives: Botany of a Fruitcake

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