In a bowl, mix all the dry ingredients together - flour, baking powder, baking soda and cinnamon powder.
In another bowl, mix the sugar and oil very well, add the applesauce and vanilla extract and again mix well so all the ingredients will combine well.
Add the apple cider vinegar to the sugar oil applesauce mixture and stir well to combine and blend with the other ingredients.
Transfer the wet mixture of applesauce and other ingredients to the dry flour mixture, mix well using a balloon whisk to combine all ingredients without any lumps.
Grease the cake pan with oil and transfer the prepared batter to the greased cake pan.
Sprinkle the extra cinnamon powder on top of the batter evenly.
Bake in the preheated oven for about 30 minutes or until the top is browned and a toothpick inserted through the center of the cake comes out almost clean (some moisture is fine as this is a moist apple cake made using applesauce).
Allow the cake to cool down in the rack before you transfer it from the cake pan and frost if you like and slice as needed.
Enjoy the warm or chilled applesauce vanilla cake with a cup or tea or coffee or milk!