Heat butter, sugar, fruit, sherry, spice, baking soda and syrup in a large saucepan. Heat over a medium heat for 2 minutes, stirring often. Allow to cool fully (at least 1 hour).
Heat oven to 125°C conventional bake. Grease 2 x deep 20cm round tins (or 2 x regular 30cm tins) and triple line with baking paper, ensuring the paper extends up the sides beyond the tin.
Beat eggs and stir through cooled fruit mixture. Sift dry ingredients and fold into fruit mixture with orange zest.
Spoon into tins, bake for approximately 3 -3 ½ hours or until cooked when tested with a skewer. Decorate once cool.
Tip: Place a double layer of baking paper across top of tin to prevent cake browning too quickly (avoiding contact with cake mixture).
Note: We have updated this recipe to make it easier to bake by spreading it across two cake tins. You can still make it as one cake, just use a larger tin and allow for a longer cooking time (approximately 4 hrs) and check it regularly.
Store in an airtight container in a cool, dry place. Wrap in tin foil, and then cheesecloth. Will keep for at least a year and stays deliciously moist.