Preheat the oven to 180ºC/350F and greaseproof a bundt tin with butter and lightly sprinkle with flour to coat the inside of the tin.
Place the butter and sugar into a bowl and beat on medium until pale and well combined, approximately 3 minutes.
Add in the egg yolks and whip until well combined, a further 1 minute.
Add the coconut milk and desiccated coconut, and beat until combined.
Sift the flour, baking powder, baking soda and salt into the bowl and beat on low until just combined.
In a separate bowl, whip the egg whites until soft peaks form.
Add half the cake batter to the whipped egg whites and gently fold the until it is a smooth mixture and fully incorporated, continue with the remaining coconut mixture until the cake is nicely combine and smooth.
Spoon into the prepared cake tin and tap a few times to release any air bubbles.
Place in the oven and bake for 35 minutes until golden or a skewer comes out clean.
Remove and allow to cool for 5 minutes before turning out onto a cooling rack. Set aside to cool completely.