Preheat oven to 350°F. Spread walnuts on baking sheet and bake until lightly toasted, 8 to 10 minutes. Remove from oven, cool slightly and chop coarsely; set aside. Lightly brush three baking sheets with oil or line with parchment paper; set aside.
In large bowl, mix both flours, baking powder, cardamom and salt; set aside. In food processor, combine maple syrup, cocoa, oil, soy milk, vanilla and flaxseeds and process until well blended.
Add maple mixture to flour mixture and stir until well blended. Stir in chocolate chips and chopped walnuts. Drop dough by level tablespoonfuls onto prepared baking sheets, spacing about 2 inches apart. Bake until set, about 15 minutes. Transfer cookies to wire racks to cool.