Mix all dry ingedients together in a very large pan or bowl.
Melt butter and golden syrup together in a pot until just boiling.
Blend the bicarb with the boiling water, stirring to dissolve.
Remove butter mixture from the heat and add the bicarb mix. Stir gently, and add to the dry ingredients. Blend in well with a wooden spoon, and then use your hands to mix in completely.
Mould mixture into large tablespoon sized balls - It is important to really squeeze the mixture into a firm ball to ensure a firm biscuit that will not crumble & fall apart after baking. Flattern the balls slightly on the baking tray - keeping their round shape. Bake at 180 C / Gas 4 for 10-15 minutes.
Cool on a rack. When cool these are even more delicious when you half dip then in melted dark chocolate! These keep really well in an airtight container.