Preheat oven at 350-degree Fahrenheit and prepare two 8 inches cake pans by greasing them or placing the parchment paper inside them. In a mixing bowl combine all the dry ingredients for the cake and mix well with a spoon.
In another bowl combine all the wet ingredients (except milk) in a bowl and whip it well with a spoon.
Now, fold in wet ingredients into dry ingredients and whip it with a spoon. Now, add oat milk to it and whip it well until a thick smooth batter is formed.
Pour the batter equally in the two cake pans at their center. Then tap them gently to evenly spread the cake all through the pan. Place them in the middle rack of the oven and bake them for 30 minutes or until the testes comes out clean. Once done, turn it off and take the cake pans out of the oven. Let them cool down completely for an hour in the cake pan without disturbing.
In the meanwhile, combine all the frosting ingredients in a blender and blend it smooth. Spoon it out in a bowl and refrigerate until ready to use.
Now, invert the cake pans and place the cakes on a flat surface. With the help of a butter knife spread ¼ of the frosting on the top of the 1st cake.
Place the second cake on it and cover the entire cake with the frosting with the butter knife.
Now, mix the ingredients for garnishing in a small bowl and put it into a small sieve. Tap it and spread the spice all over the top of the cake. Decorate with pecans.