For the dough: In a mixing bowl, whisk together 4½ cups/675g of the rice flour and ½ cup/60g of all-purpose flour with the boiling water until you have a grainy paste, then set aside.
In a food processor, mix the sugar and butter until creamy. With the machine still running, add the saffron-rose water, vanilla, and the egg yolks (one at a time, allowing