Preheat oven to 350°F.
Grind walnuts in blender.
Prick eggplants all over with skewer or toothpick, place in a microwave safe bowl and cover with plastic wrap. Microwave for 8 minutes until limp. Drain excess water.
Puree eggplant in blender, while still quite warm, add chopped chocolate and set aside to let chocolate melt completely.
Mix all other ingredients together in a large bowl. Gently and gradually add eggplant and chocolate mixture into bowl until thoroughly mixed.
Grease 8 inch square baking tin with non-stick spray. Pour mixture into tin and bake on bottom rack of oven for 30-40 minutes, or until inserted toothpick comes out clean. Remove from rack and let it cool before removing from tin.
Garnish with icing sugar on top and serve.
For extra sweetness, serve warm brownie with a scoop of vanilla ice cream!