Preheat oven to 350 degrees Fahrenheit.

Line a nine- by 13-inch pan with Gefen Parchment Paper.

In a large bowl mix sugar, flour, cocoa, baking powder, baking soda and salt. Add eggs, soy milk, oil and vanilla, and mix on medium speed for two minutes.

Pour in boiling water and mix for another minute.

Pour batter into the pan. Bake for 30-35 minutes. Allow it to cool completely, then remove cake from the pan, trim to straighten the edges, and cut it in half horizontally so you end up with two nine- by 13-inch sheets of cake.

Combine cocoa powder and hot water and mix well.

Place chocolate chips in a double boiler and stir until smooth. Add cocoa mixture and stir to combine. Allow to cool to room temperature.

In a separate bowl, beat the whip and sugar until stiff. With a spatula, fold in the chocolate mixture until well combined. Refrigerate for one hour.

Place one sheet of cake on a tray, spread a thick layer of mousse over it, then cover it with the second sheet of cake. Refrigerate for 30 minutes.

Cut cake into two logs and spread the remaining mousse filling evenly around the entire outside and top of the cakes. Refrigerate.

In a medium saucepan, add soy milk, cocoa and margarine. Bring to a boil.

Remove from heat, add powdered sugar, and use a hand mixer to get rid of any lumps.

Allow it to cool for 15-20 minutes, stirring occasionally.

Pour chocolate frosting over the top of the cakes. Use a spatula or butter knife to gently spread it evenly across the top.