Preheat oven to 350 degrees and spray (3) 9 inch cake pans with baking spray
In a large bowl mix all cake ingredients until smooth and combined. Evenly divide between pans.
Bake for 28-32 minutes or until done. Cool completely.
For the Topping
In a small microwave safe bowl melt butter. In another medium bowl mix cinnamon and sugar.
Using a cake leveler to make the cakes even and flat. Brush with melted butter and sprinkle with cinnamon sugar. You may not use all of the butter or sugar mixture.
For the Frosting
In a large bowl cream butter and powdered sugar. Add cinnamon, salt, and vanilla. Then stir in heavy cream until you reach your desired consistency.
Spread around 1 cup of the frosting on each layer and spread until smooth.