The rich flavor of chocolate eclipses the fact that no eggs, butter or refined sugars are used to make this dense, fudgy confection. Flaxseeds are available at natural food stores.
Preheat oven to 350°F. Grease two 9-inch round cake pans and coat with flour, tapping out excess flour.
In large bowl, mix flour, cocoa, baking powder and baking soda.
In food processor or blender, grind flaxseeds to fine powder. Add 1/2 cup water and process until thick and frothy, about 30 seconds. Add dates and their soaking liquid, tofu, maple syrup, oil and vanilla, and process until smooth. Transfer mixture to large bowl.
Stir dry ingredients into wet ingredients, blending until smooth, Divide the batter evenly between prepared pans.
Bake until cakes spring back when lightly pressed, 20 to 25 minutes. Cool cakes in pans on wire rack 10 minutes; then invert onto wire racks, remove pans, and cool completely.
Make frosting: In top of double-boiler set over simmering (not boiling) water, melt chocolate, stirring until smooth. Remove from water and set aside.
In food processor or blender, finely grind cashews. Add 1/3 cup water and blend until smooth. Add tofu, maple syrup and vanilla, and process until smooth. Add melted chocolate and process until smooth. Transfer to medium bowl and refrigerate until chilled.
To frost cake, spread about 2/3 cup frosting over top of one layer. Cover with second layer and spread top and sides with remaining frosting. Cut into wedges and serve.