Preheat the oven to 350 degrees Fahrenheit. Grease and line three 8 inch cake pans and set aside.
In a large bowl, beat together all wet ingredients except for the apple.
Beat in the dry ingredients, making sure to spoon and level the flour, don't scoop right from the bag.
Once well combined, fold in the grated apple until well combined.
Evenly to your prepared pans and spread the top.
Bake for 25-32 minutes or until a toothpick comes out clean with a few moist crumbs.
Let cool in the pan for just 15 minutes, then flip onto a wire rack to finish cooling.
Let cool completely.
To make the buttercream, add the butter to a large mixing bowl or bowl of a stand mixer. Beat for about 1 full minute. Add in the cinnamon and powdered sugar. Beat until well combine. Finally, add in the cream, maple syrup and vanilla and beat until fluffy. If it is too thick, add more cream, if you want it thicker, add more powdered sugar.
Add frosting between each cake layer, than around the top and sides. I topped with some caramel sauce and crushed sliced almonds, but it's also great plain or with some crushed dried apples!