Grease 3-7" cake pans & line with parchment paper & preheat the oven to 350°F
First combine the cocoa powder & the oil together in a small bowl &whisk smooth~ reserve
Now prepare the white cake recipe by combining the softened vegan butter with the coconut oil in the bowl of your electric mixer with the paddle attachment & cream on high speed to incorporate to the same consistency *it is ok if the coconut oil is not solid
Now add the granulated sugar & cream on medium to high speed for approximately 5 minutes until light and fluffy, be sure to scrape the bottom & sides of the bowl from time to time.
Combine the plant milk with the vinegar & the extracts
Combine the aquafaba with the cornstarch and whisk together so there are no lumps
Once the butter mixture is creamed, slowly add the aquafaba/cornstarch to it until it is all incorporated then whip on high speed for 30 seconds to emulsify, the mixture will get very silky, fluffy and smooth
Sift the flour with the salt, baking soda & baking powder & then add 1/3 of it to the creamed mixture, blend just until combined then add half of the milk mixture
Add another 1/3 of the dry ingredients & then the remaining liquid & the last of the remaining dry ingredients.
Be sure to scrape the sides & bottom of the bowl and whip it on high for 10 seconds to blend well.
Next take out 420g (or 1/3) of the batter into a medium bowl & add the cocoa paste to make the single chocolate layer
Next divide the remaining white batter amongst the 2 prepared cake pans and the chocolate layer into the 3rd cake pan
Bake immediately in the preheated oven that has been set to 350°F but once the cakes are loaded turn the oven temperature down to 325°F & bake for a total of 25-30 minutes or when a toothpick inserted into the center comes out clean.
Cool in the pans and then turn them out onto a cooling rack to cool completely
Prepare the buttercream and ganache recipes as per the instructions on that recipe
Assemble the cake as per the video tutorial
Video
Notes
Storage Chocolate Eclair Cake can be stored at a cool room temperature for up to 2 days, for longer storage refrigerate wrapped to prevent drying for up to 1 week