Preheat oven to 180ºC. Place the flour, desiccated coconut, sugar and 140g butter in a bowl and stir until the mixture resembles coarse breadcrumbs.
Using the back of a spoon, press the mixture into the base of a 20cm x 30cm tin lined with non-stick baking paper and bake for 20–25 minutes or until golden.
Allow to cool for 10 minutes. Place the shredded coconut, oats, golden syrup, and remaining butter in a bowl and mix to combine.
Spread the caramel over the cooled base and spoon over the oat topping. Bake for a further 20–25 minutes or until golden.
Allow to cool completely before cutting into squares to serve.