In a bowl mix together all the dry ingredients flower, baking powder and soda.
In a large bowl or stand mixer beat together butter and sugar until fluffy. After a few minutes scrap down sides and add in apple sauce and vanilla extract.
Mix until combined and slowly add flour mixture and butter milk until smooth and well combined.
Add batter into a pan and bake in a preheated oven of 350 degrees for 25-35 minutes or until toothpick comes out clean.
allow cakes to completely cool before adding frosting.