1. Preheat oven to 350°F, and coat 2 baking sheets with cooking spray.
2. Process wild rice in food processor 1 minute, or until coarsely chopped. Set aside.
3. Whisk together brown rice flour, cornstarch, baking soda, cinnamon, ginger, salt, and nutmeg in large bowl. Set aside.
4. Cream margarine, brown sugar, and sugar in bowl with electric mixer until smooth and fluffy. Beat in egg and vanilla. Add flour mixture, and beat until smooth. Stir in wild rice, dried cranberries, and walnuts.
5. Scoop 2-Tbs. dollops of batter 11/2 inches apart on prepared baking sheets. Bake 8 to 10 minutes, or until cookies are browned and dry on top. Cool 1 minute on baking sheets, then transfer to rack with spatula, and cool completely.