• Prepare a jelly roll pan (about 15.5 x 10.5 inches) with parchment paper.
• Preheat oven to 400° F.
• In a small bowl, mix together the egg substitute and set aside.
• Combine the flour and sugar in a medium mixing bowl and set aside.
• Mix together, in a measuring cup, the milk and lemon juice, set aside to curdle (this is the vegan buttermilk).
• In a small sauce pan, on a medium heat, blend together, water, oil, margarine, and cocoa powder, bring to a boil and then remove from heat.
• Pour the boiled mixture over the flour and sugar, then add the vegan buttermilk, baking soda, egg substitute, cinnamon, and vanilla and blend until smooth.
• Once the batter is smooth, pour it into the jelly roll pan and slide into the oven.
• Bake for 20 minutes.
• While the cake is baking, start the frosting about 5 minutes before the cake is done.
• You'll want the frosting to be ready when the cake comes out of the oven.
• As the frosting needs to be poured onto the cake while it's still hot. The timing is important here!

How to make the frosting

• Mix together, in a measuring cup, the milk and lemon juice, set aside to curdle (this is the vegan buttermilk).
• In a small sauce pan, add the vegan margarine, cocoa, and the vegan buttermilk, bring to boil.
• In a small mixing bowl, pour the boiling mixture into the mixing bowl and slowly add the powdered sugar while blending.
• Lastly, add in the vanilla extract, blend until smooth.
• Once the cake is done baking, pour the frosting over the cake.
• Make sure to do this right after you take it out of the oven.
• This is a must, this is so that the frosting spreads evenly and easily.
• Leave the cake to cool completely before slicing into and serving.