Cook the rice: Put the rice, 2 cups of water, and the salt in a medium saucepan with a tight- fitting lid. Bring to a boil- you should hear the pot going all a flutter under the lid and puffing steam out the seam. Reduce to a low simmer, and let the rice cook for 15 minutes, until the water is absorbed. Remove the rice pot from the heat.
Once the rice is cooked, whisk the egg in a medium bowl, and then whisk in the evaporated milk. Stir the coconut and sweetened condensed milks into the rice, then add the egg mixture. Return the saucepan to heat and cook the mixture over medium- low heat until it looks mostly, or about 90 percent, absorbed (the pudding will thicken a lot as it cools), about 20 to 25 minutes. Stir in the vanilla extract, then divide the pudding among serving dishes. Keep the puddings in the fridge until fully chilled, about 1 to 2 hours.
To serve: Whip the heavy cream with the confectioners' sugar until soft peaks form. Dollop a spoonful of whipped cream on top of each bowl of rice pudding, dust with ground cinnamon, then enjoy.
Cook's Note: If you have 2 cups of leftover white rice, you can skip the first step, and jump in with the egg and three milks.