Toast the coconut flakes in a dry skillet, stirring frequently, until browned and fragrant, 6 -7 minutes. Set aside to cool.

Mix ½ cup of the coconut milk with the cornstarch. Set aside. In a large mixing bowl, whisk the egg yolks.

In a medium saucepan, combine the remaining coconut milk with the coconut sugar and salt. Heat the mixture over medium-high heat until it just comes to a boil. Gradually pour about ½ cup of the heated coconut milk mixture into the egg yolks and whisk well. Pour the egg yolk mixture back into the saucepan with the coconut milk and add the cornstarch mixture. Bring the mixture back up to a gentle boil, whisking constantly. Once the mixture starts to boil, cook for 1 – 2 more minutes or until the mixture is the consistency of pudding. Remove from the heat and add the vanilla and rum. Pour the mixture into the cooled pie crust and lay a piece of plastic wrap over the pie, pressing the plastic wrap directly onto the surface of the filling to prevent a skin from forming. Refrigerate until the filling is completely cooled and set, about 2 hours. Remove the plastic wrap and sprinkle the top of the pie with the toasted coconut flakes.