Heat butter a medium sized, heavy saucepan over medium heat. When butter is melted, add brown sugar and salt, stir until dissolved. Turn heat to high, add rice and stir until all grains coated evenly.
Add coconut milk and water. Stir. When boiling, immediately cover with tight fitting lid, turn heat to medium-low and simmer undisturbed for 20 minutes.
Remove pot from heat but do not open lid. Really, no peeking! Let sit for 10 minutes. While rice is cooking, toast coconut flakes on a dry skillet over medium high heat.
Stir frequently to avoid burning, remove from pan as soon as coconut is golden brown, about 2 minutes.