1. Line the bottoms of four 8 inch cake pans with parchment paper and grease the sides. Preheat oven to 350 degrees.
2. Cream together butter and sugars for about 2-3 minutes, until light and fluffy.
3. Add eggs one at a time and mix until incorporated.
4. Add vanilla, apple pie spice and cinnamon and mix until incorporated.
5. Alternate adding the flour and buttermilk, beginning and ending with flour, mixing until combined.
6. In another bowl, mix together baking soda and vinegar. Add mixture to batter and mix just until incorporated.
7. Spread batter evenly between the 4 pans and bake for 15-17 minutes.
8. Remove pans from oven when done and allow to cool for 2-3 minutes, then remove to cooling rack to finish cooling.
9. While the cakes cool, make the caramel. Add the sugar in an even layer to the bottom of a large saucepan.
10. Heat sugar on medium-high and whisk until the sugar has melted, about 5 minutes. The sugar will lump together, but eventually melt.
11. Continue whisking until the temperature reaches 350 degrees or the sugar has turned an amber color. It will reach 350 degrees very quickly after all the sugar has melted. Watch it very closely. It goes from nice caramel to burned very quickly.
12. Remove caramel from heat and add butter. Whisk until melted and combined. Mixture might bubble a bit.
13. Add the heavy cream and whisk until incorporated.
14. Cool caramel to room temperature.
15. When caramel and cakes are cool, cook apples. Combine apples, lemon, nutmeg, cinnamon and brown sugar in a medium pan and toss to coat.
16. Add butter and cook apples for about 25-30 minutes, stirring often, or until at preferred softness.
17. Remove from heat and allow to cool for about 30-40 minutes. I recommend putting the apples into another bowl to stop them from cooking more.
18. Once apples are cooled, it’s time to stack the cake. Place the first cake layer on your cake plate.
19. Spread about 4-5 tbsp of caramel sauce over the top of the cake layer and allow it to soak in.
20. Spread 1/4 of the apples in an even layer on top of the layer of cake.
21. Repeat steps 18-20 with the remaining layers of cake and apples.
22. Drizzle more caramel over the top of the cake.