Begin by preheating the oven to 350. Grease the metal cake pans with non-stick cooking spray.
In a mixing bowl, mix the mix, butter, sugar, vanilla, baking powder, baking soda, and pinch of salt together. Add the flour and mix until a smooth batter is formed. Divide the batter in half by transferring half of it into a separate mixing bowl.
In one of the batter bowls, mix in cocoa powder and red food coloring until well combined. Add as much coloring as you need to get the cake batter red.
Alternate adding the plain batter and the red batter into the cake pans to create a marble effect. Fill each pan about ⅓ of the way full. Bake in the oven for 25 minutes or until it is completely cooked through the center.
While the red velvet cakes bake, use a whisk or ideally an electric hand mixer to mix the vegan cream cheese frosting ingredients. Set aside.
Once the cakes are done baking, remove them from the cake pans carefully and then allow them to cool on a wire rack. Stack the layers on top of each other, frosting in between. Then, frost around and on top of the cake. Decorate as desired.