Step 1: Preheat your oven to 350°F (175°C) and grease a 9-inch round cake pan or a loaf pan with butter and a dusting of flour.
Step 2: In a large bowl, cream together the softened butter and granulated sugar until the mixture is light, fluffy, and pale in color.
Step 3: Add the eggs one at a time, beating well after each addition to ensure they are fully incorporated into the butter mixture.
Step 4: Stir in the rosewater and vanilla extract until well combined.
Step 5: In a separate medium bowl, whisk together the flour, ground pistachios, baking powder, ground cardamom, and salt.
Step 6: Gradually add the dry ingredients to the wet ingredients, alternating with the milk, starting and ending with the flour mixture. Mix until just combined.
Step 7: Pour the batter into the prepared pan and smooth the top with a spatula.
Step 8: Bake for 40-45 minutes, or until a toothpick inserted into the center comes out clean.
Step 9: Allow the cake to cool in the pan for 10 minutes before transferring it to a wire rack to cool completely.
Step 10: Whisk the glaze ingredients together and drizzle over the cooled cake. Garnish with pistachios and rose petals before the glaze sets.