In a medium bowl whisk together the Rice Flour and Granulated Sugar until evenly combined.
Stir a small amount of the Whole Milk into the dry mix to make a smooth, lump-free slurry.
Heat the remaining Whole Milk in a heavy-bottomed saucepan over medium heat until it is warm and starting to steam (do not let it boil).
Slowly pour the warm milk into the slurry while whisking, or pour the slurry into the saucepan, whisking constantly to prevent lumps.
Return the saucepan to medium heat and cook, stirring continuously, until the mixture thickens to a pudding-like consistency and just begins to bubble gently—this usually takes a few minutes.
Remove from the heat and let the pudding cool slightly, then divide into individual serving bowls or ramekins.
Refrigerate until fully set and chilled, at least a couple of hours.
Just before serving, dust the tops with Ground Cinnamon and sprinkle with chopped Pistachios for color and crunch.
