In a large mixing bowl, add eggs, buttermilk, oil and mix until you have a frothy, bubbly mixture.
Add cake mix and apple pie spice and mix until just combined. Do not over mix!
Pour batter into two round greased and floured cake pans (Dimension: 8x2).
Bake at 350 degrees F for about 40 minutes on until an inserted toothpick in the center comes out clean. The tops will be golden brown.
Allow the cakes to cool completely at room temperature.
Trim the domes of both cakes (if any) to make them flat. Also, if you like, you can trim the sides of the cake. I did that in the pictures but not in the video. Both ways work well.
Place one cake on a cake stand.
Use a spatula to frost the top of this cake with buttercream. You can also fill a piping bag with the large star tip (Wilton tip 1M) and pipe buttercream stars instead of using a spatula.
Gently spread some apple pie filling on top of the frosting.
Place the other cake on top of the pie filling and press gently to secure properly.
Spread more buttercream on top, followed by apple pie filling.
Decorate the top of the cake with a few cinnamon sticks.
Optional: Toss some shredded white chocolate around the base of the cake and enjoy.