In a small pot, place the butter and golden syrup over low heat until the butter is completely melted (about 2mins).
Turn off the heat then add the bicarbonate of soda and stir to combine. Set aside to cool down for 5 mins.
In a large bowl, combine the plain flour, rolled oats, desiccated coconut, caster sugar and brown sugar. Stir to combine everything then make a little well in the middle.
In the same bowl, pour the melted butter and syrup mixture in the middle. Use a wooden spoon or spatula to stir well until it forms a crumbly and sticky mixture (add a tbsp of water if it feels too dry).
Grab a spoonful (about 30g) of the biscuit mixture and rolled it with your hands to make little balls. Place the balls onto a baking tray and gently press each one to flatten them slightly.
Bake the biscuits in the oven at 180°C fan forced for 12 minutes or until golden brown.
Video
Notes
For crunchy biscuits, only use caster sugar! For chewy biscuits, only use brown sugar!