Reserve 2 tablespoons of shredded coconut to garnish glasses. Lightly toast the remaining shredded coconut and set aside.
Reserve 2 tablespoons of full cream coconut milk. If the remaining coconut milk has solids in it, as it often does out of a can, melt it briefly in a small pan on top of the stove, then set aside.
With the reserved coconut milk, brush a little around the rim of the glasses and dip in reserved shredded coconut. Place the remaining coconut milk into a small saucepan and melt the sugar in it, to form a coconut syrup, set aside and cool.
In a shaker, place the ice, cachaca, coconut syrup and coconut milk and give a good hard shake. Pour into two glasses and top with toasted shredded coconut and serve.