Preheat oven to 375 F.
1/2 cup vegan margarine or shortening
1 banana, mashed (I don't use a VERY ripe one - this adds a subtle banana flavour)
1/4 cup oil
2-3 tbsp water
3/4 cup dry sweetener (you could use a liquid sweetener as well, omitting the oil and possibly the water)
2 tsp vanilla
Mix above ingredients in a medium size bowl - the banana adds extra liquid, so you may want to hold back the water unless you need it.
In a seperate bowl, mix:
2 1/4 cups whole wheat flour
1 1/2 tsp baking soda
1/2 tsp salt
Add the dry indredients to the wet and mix - the dough should be somewhat sticky but hold its shape when dropped from a spoon with no flattening. Use your cookie intuition :) - sometimes I have to add more water, sometimes more flour.
Finally: add 1/2 to 3/4 cup each chocolate chips and chopped walnuts. Mix it in.
Drop small spoonfuls of the batter onto an unoiled or very lightly oiled cookie sheet and flatten. The book says this will make twelve "small" cookies... I made forty-four. If you make them small like me, bake them for 7 minutes, 8 at most. They should be very lightly browned when you pull them out of the oven, and they'll stay soft. If you make them larger, don't bake them for any longer than 10 minutes.
Variation: You can omit the margarine and the banana and replace them with peanut butter, adding extra oil (ick) or soymilk/water to get the right consistency.