1. Preheat oven to 350°F.
2. In a large mixing bowl, whisk together the flour, sugar, cornstarch, ginger, cardamom, and salt.
3. Add the oil, rosewater, and vanilla extract and mix until a dough forms.
4. Fold in the rose petals and optional crushed nuts.
5. Form a ball of dough about 1/2 inch and then flatten in with your hands to make the cookies. You should have about 12 cookies.Optionally, use a small cookie cutter or knife to cut fun shapes into them such as hearts and stars.
6. Place cookies on prepared baking sheet and bake for 20 minutes.
7. Remove from oven and place on a cooling rack. Sprinkle with optional rose petals.