Preheat oven to 180 C / Gas 4. Grease and flour a 25cm tube cake tin. Sift together the flour, salt, cinnamon, nutmeg and allspice. Set aside. Dissolve 1 teaspoon bicarbonate of soda in 2 teaspoons hot water; set aside.
In a large bowl, beat eggs with electric mixer until thick and lemon coloured. Beat in 300g sugar and 240ml oil. Combine buttermilk and dissolved bicarbonate of soda. Beat in the flour mixture alternately with buttermilk mixture. Stir in 1 teaspoon vanilla, figs and nuts. Pour into prepared cake tin.
Bake in the preheated oven for 70 to 75 minutes. Remove from tin and pour hot buttermilk icing over warm cake.
To make buttermilk icing:
In a heavy saucepan combine 200g sugar, 120ml buttermilk, 1/2 teaspoon bicarbonate of soda, golden syrup and butter. Bring to the boil and cook without stirring until mixture reaches soft-ball stage (115 C on a sugar thermometer). Remove from stove and stir in vanilla. Pour over warm cake.
If you don't have a sugar thermometer, no worries! Check soft-ball stage (when making icing) by dropping a small amount of the hot icing mixture into cold water; when it forms a soft ball which will flatten on its own when removed, it's ready!