Make the cake: Preheat your oven to 350°. Butter and flour or spray three 6” inch pans {or two 8” or 9” pans}, and set aside. In a medium size bowl, combine the butter and sugars. Mix well, about 30 seconds. Add eggs, mixing until they are incorporated, about another 20 seconds. Add spices, salt, baking powder, and both flours. Mix until just incorporated. Fold in apples.
Divine batter evenly between 3 pans. Bake for 25-30 minutes, or until a toothpick comes out clean and the edges are a golden brown. Allow to cool in pans for 15 minutes. Remove from pans and cool on wire rack completely.
Make the frosting: With a standing or hand mixer, mix butter and creamy, about 30 seconds. Add vanilla, powdered sugar, and salted caramel sauce, then mix until well incorporated, about 30 more seconds. Spread or pipe onto cooled cake.
Follow steps in the blog for how to make the candy melt trees. Place trees on cake and serve immediately. Store any leftovers covered at room temperature for up to three days. Enjoy!