Preheat oven to 160°C (fan-forced) or 180°C. Line biscuit trays with baking paper or grease lightly.

In a large bowl, combine rolled oats, desiccated coconut, plain flour, and sugars.

In a saucepan or microwave, melt butter and golden syrup together.

In a cup, mix boiling water and bicarbonate of soda. Add to the melted butter mixture; it will foam.

Add the butter mixture to the dry ingredients and combine thoroughly.

If the mixture is too crumbly, add a small amount of water until it holds together.

Roll the mixture into balls and flatten slightly.

Place on baking trays and bake for 15-20 minutes, or until golden brown.

Cool on trays for 5-10 minutes before moving to a wire rack to cool completely.

If biscuits are too soft, return them to the oven for further baking.