Preheat the oven to 350 degree Fahrenheit.
In a bowl, beat well the eggs.
Add the mashed sweet potatoes, mix well.
Add the brown sugar and mix the ingredients well.
Add the oil, mix again.
Add the milk, vanilla essence and cinnamon powder to the bowl and mix everything well.
In another large bowl, mix together the dry ingredients - flour, salt, baking powder and baking soda (you may also add some extra cinnamon powder if you like) until all ingredients are evenly mixed.
Add the wet ingredients mixture to the dry ingredients mixture, mix together to form the batter without forming any lumps.
Also add the white sugar to the batter, mix enough to blend in the sugar evenly across the batter.
Transfer the cake batter to a greased caked pan, bake for about 40 to 45 minutes or until a toothpick inserted at the center of the cake comes out clean. If the top of the cake is cooked before the inside is cooked completely, cover the pan with an aluminium foil and bake for the rest of the time. It is a good idea to check the cake after 25 minutes of baking time, since I had to cover the pan with foil at that point.
Allow the cake to cool down before you cut or apply the frosting.