Preheat oven to 350˚F.
For cake: Place flour, baking powder, baking soda, and salt into a mixing bowl.
Place sugar, butter and eggs into another mixing bowl and whisk together. Pour the flour mixture into the egg mixture and whisk together until very thick and combined.
Stir in the remaining ingredients , except the apple and cranberries, until fully incorporated and the batter is smooth.
Gently fold in the apple and cranberries until evenly distributed.
Pour the batter into four prepared cake pans (bottoms lined with parchment and lightly greased) and bake for 25 to 30 minutes or until a toothpick comes out clean when inserted into the center of the cake.
Allow the cakes to cool in the pans for 15 to 20 minutes before removing from pans and allowing cakes to cool completely.
For buttercream: Place butter into a stand mixer with a paddle attachment and whip until light and fluffy. Add sugar, ½ cup at a time, until fully incorporated. Add the remaining ingredients, scrap down the sides of the bowl, and continue to whip until smooth (the frosting should be on the runny side…not firm enough to pipe, but not so runny that it can’t sit, spread atop a cake).
To assemble: Place a thin layer of buttercream over the top of one of the cakes and top with the other cake, inverted (so both cake circle tops are touching one another). Repeat with remaining cake layers, so all four are stacked atop one another.
Gently frost the four tiered cake with a thin layer of frosting (the crumb coat). Place in the refrigerator for at least 30 minutes.
Coat the cake in another layer of frosting and smooth the frosting on the top of the cake. Top the cake with a border of fresh sage leaves and cranberries to look like a wreath. Slice and serve.