In a saucepan, combine all the ingredients for the glaze. Bring to a boil, stir gently, simmer for a few minutes, remove from heat and set aside. Preheat the oven to 350°F (180°C). Butter an 8-inch spring form cake pan and line the base with parchment paper. Then butter and dust the top of the parchment paper. In a mixing bowl, whisk the egg yolks and sugar until creamy. Add the cardamom, rose water, milk, and oil, and whisk for 1 minute longer. Add the flour, pistachios, and apple, and fold in with a rubber spatula. In a separate mixing bowl, whisk the egg whites until there are soft peaks. Fold into the flour mixture until you have a smooth, light batter. Gently pour the batter into the cake pan and bake for 40 to 45 minutes until a tester comes out clean. Remove the pan from the oven and place it on a cooling rack. Pour half of the glaze over the cake and leave the cake in the pan until it has absorbed all the syrup. Tap the pan to release the cake and transfer to a serving dish. Cut into diamond shapes, pour the remaining glaze over the cake, and decorate with pistachios, almonds, and rose petals.