Preheat the oven to 160 C and line a baking tray with parchment paper.
In a bowl, mix almond flour, sugar, and salt until smooth.
In another bowl, beat the egg white until foamy, then add vanilla extract and rose water.
Gently fold the almond mixture into the egg white until you get a soft, sticky dough. Do not overmix.
Shape small balls of dough, place on the baking sheet, and flatten slightly. Garnish with chopped pistachios.
Bake for 15-20 minutes, until the edges turn lightly golden. Avoid overbaking.
Let the cookies cool on a wire rack, then dust with powdered sugar and serve.