First grease & parchment line your 3-7" cake pans & preheat the oven to 350°F
Prepare the banana cake layers by combining the softened vegan butter with the sugar in a large mixing bowl or with a stand mixer & the paddle attachment.
Cream on medium to high speed until light & fluffy this should take approx 4-5 minutes.
Meanwhile combine the room temperature plant milk with the vinegar
Sift together the flour(s) with the cinnamon, baking soda, baking powder & salt. I add the dry blend egg replacer to my dry ingredients I do not reconstitute it
Once the butter/sugar is light & fluffy scrape the bottom & sides of the bowl and then add the mashed banana
Whip on high speed to emulsify & then scrape the bottom & sides of the bowl again
Now add 1/3 of the sifted dry ingredients while mixing on low speed & mix just until incorporated, then add half of the plant milk mixture
Add another 1/3 of the dry & then the remaining milk ending with the last addition of dry ingredients
Whip on high for 5 seconds to develop the batter then divide the batter between 3-7" cake pans
Bake for approximately 25-30 minutes or when the cakes are springy to the touch when you gently press the centers or when toothpick inserted comes out clean
Cool the cakes while you prepare the ganache recipe according to the recipe on that post
Once the cakes are almost cold, prepare the custard filling by combining the cornstarch with the sugar in a medium sauce pot & then add the plant milk
Bring to a rolling boil over medium to high heat whisking constantly to avoid burning the bottom
Once the custard starts to bubble remove from the heat & whisk in the vanilla extract
Set up your cake ring with the acetate strip & place 1 layer of cake in the bottom then pour half of the custard over top
Allow it to set for 5 minutes in the refrigerator before adding the next cake layer & the remaining custard
Then top with the last cake layer and refrigerate for 1 hour to set
Once the cake is sturdy enough and set, pour the ganache over top & let some drip down the sides
Garnish with lightly toasted walnuts