In a large bowl, cream together butter and sugar until light and fluffy, about 5 minutes. Beat in eggs and rosewater. Stir in the rose petals, then the flour, baking powder and salt. Cover, and chill dough for at least 1 hour (or overnight).
Preheat oven to 200 C / Gas 6. Line baking tray with baking parchment.
Roll out dough on floured surface to about 5mm thick. Cut into shapes with a shaped cutter, or simply cut into rectangles or squares. Place biscuits 2.5cm apart on baking tray.
Bake 6 to 8 minutes in preheated oven. Cool completely.