Preheat oven at 350-degree Fahrenheit and prepare two 8-inch round cake pans by greasing them. Parchment paper would not work here as the cake might get sticky. In a mixing bowl combine all the dry ingredients. Mix them very well making sure there are no lumps and keep it aside.
In a blender combine all the wet ingredients (beetroots, oat milk, vanilla, dates, soaked chia seeds, maple syrup and apple cider vinegar). Blend them smooth and keep it aside.
Now, fold in the wet ingredients into the dry ingredients and whip it into a soft yet thick batter.
Spoon it out equally in the two prepared cakepans. Then, tap and shake cake pans by rotating them with both hands so that the batter equally spreads in the pan taking its natural shape. Do not disturb its top or else the cakes will crack. Place them in the middle rack of the oven and bake for 25-30 minutes or until the tester comes out clean. Turn it off and take out the cakes. Place them on a flat surface and let them cool for 15-20minutes without disturbing.
In the meanwhile, drain the cashew nuts and blend the frosting ingredients smooth. It should be thick and creamy and firm. If needed you may add another 2 tbsp. oat milk to blend it easily but do not exceed. Scrape from all side at intervals and press the ingredients so it blends absolutely smooth and creamy. Spoon it out in a bowl and keep it aside.
Now, invert one of the cakes on a flat surface and cover its top with the frosting.
Then, invert the other cake on the first layer and cover its top with the frosting too.
Then, cover the entire cake with the leftover frosting spreading it evenly. Slice and serve.