Preheat the oven to 375º F (180º C). Line two round cake pans of about 8.26 inches (21 cm) in diameter with parchment paper.
In a medium bowl, mix in the vegetable milk and apple vinegar and let it rest until needed. Plus, in a different bowl, sift together the flour, baking powder, baking soda and salt.
In a big dry bowl, put the aquafaba and beat using an electric mixer for 3 to 4 minutes until you get a white fluffy mixture, as if they were egg whites. Pour this mixture into a different bowl.
Now, using the same electric mixer bowl that before, cream together the margarine, oil and sugar for 3 to 4 minutes until the mixture turn lighter in color and is fluffier.
Add in the vanilla extract and beat until fully integrated. Mix in the aquafaba in three separate additions, beating for 30 seconds after each addition.
Add the flour mixture in three separate additions alternating with the vagetable milk, beating after each addition. Beat for 30 seconds more until you get a soft and smooth batter.
Divide the mixture into the two cake pans and bake for 30 to 35 minutes aprox. until a wooden stick comes out clean when inserted.
Once ready, let them sit for 10 minutes and place them on a cooling rack to cool down completely.
For the dates paste:
Place the dates in a heat ressistant bowl, add the boiling water until the dates are submerged and let them rest for 30 to 40 minutes until they are really soft.
Once soft, place the dates in a blender or food processor with some of the water and blend until you get a smooth thick paste that spreads easily.
Put the paste in the same bowl where they were before and mix in the nuts. Let it sit until it cools down.
For the pastry cream:
With a sharp knife, cut open the vanilla bean lenghtwise and carefully scrap all the seeds out.
In a pot on the stove over medium heat, pour 3/4 parts of the vegetable milk along with half of the sugar and the vanilla seeds. Let it cook for 2 minutes, making sure it doesn't boil, while whisking with a hand whisk.
In a different small bowl, using a fork, mix the rest of the milk along with the sugar, salt and corn starch.
Pour this mixture into the milk and cook over low medium heat for 4 minutes, whisking non-stop, until a thicker cream forms. It is important not to stop beating and doing it carefully for the cream to be smooth.
Remove the crem from the heat, add in the margarine and mix well. Pour the cream in a different bowl and cover it with plastic kitchen wrap (it should touch the surface of the cream for it not to form a curd or "crust") and refrigerate for 1 hour.
For the topping and to assemble the cake:
In a medium size pan over medium heat on the stove, put the dates, sugar and half the water. Let it cook, mixing non-stop with a wooden spoon for 5 minutes until the dates soften up. a little.
In a small bowl, mix the rest of the water and the corn starch, add this into the pan with the dates and cook for about 3 minutes, mixing non-stop, until a syrup forms. Remove from the heat and let the dates cool down completely.
To assemble the cake, cut the cakes in half, to get 4 round pieces of cake. Place one of the cakes on the plate (where we want to present the cake). Spread1/4 of the cream and 1/3 of the dates cream on top.
Repeat the process until you use all the cakes and end up with a layer of pastry cream. The cake is a "naked" cake, which means it will not have any frosting on the sides.
To finish, decorate the cake with the whole dates and refrigerate for at least 2 hours before cutting.