Preheat your oven to 160°C (320°F) and line a loaf tin with parchment paper.

Cream together unsalted butter and caster sugar until pale and fluffy (3-4 minutes), then blend in vanilla extract.

Combine plain yogurt and water in a separate bowl, then mix into the creamed butter and sugar until thoroughly combined.

Sift together plain flour, baking powder, salt, and green cardamom powder. Mix gently into the wet mixture, then fold in chopped pistachios.

Pour the batter into the prepared loaf tin and bake for 60-75 minutes or until a toothpick comes out clean.

Let the cake cool in the tin for 10 minutes, then transfer to a wire rack to cool completely.

Prepare the glaze by mixing icing sugar, rose water, and milk until smooth. Adjust as needed for consistency.

Drizzle the glaze over the cooled cake and garnish with additional chopped pistachios and edible rose petals if desired.