Preheat the oven to 170 degrees or Gas 3.
Line a deep 20cm x 30cm baking tin with baking parchment.
Measure the butter and the golden syrup into a large saucepan and set over a low heat until melted.
While the butter melts weigh the coconut, granulated sugar, self raising flour, salt and rolled oats into a large mixing bowl.
Remove the pan of warmed, melted butter and syrup from the stove and stir in the bicarbonate of soda. It should froth up and fizz a little. Mix it in well.
Now add the weighed, dry ingredients to the frothy butter and mix well.
Press the mixture into the tin packing down firmly.
Bake in the centre of the oven for 20/25 minutes until golden brown.
Leave to cool and little then cut into portions before completely cold.