Preheat oven to 300 degrees. Place pecans on baking sheet and toast in oven until golden, about 20 minutes. Let cool, then place in food processor and process until coarsely ground.

In medium saucepan, mix water, sugar , cocoa and couscous. Bring to a simmer and cook, stirring occasionally, until thickened and couscous is tender, 5 -10 minutes. Remove from heat and stir in vanilla. Spread mixture into an ungreased 9 - inch springform pan. Sprinkle 1/4 cups ground pecan over top. In small saucepan, melt chocolate chips over low heat, stirring constantly. When melted and smooth, transfer to blender or food processor, add tofu, and maple syrup or honey, process until smooth. Pour filling over couscous layer and top with remaining pecans.

Refrigerate until cake is set, about 2 hours. Serve cold.