• For Caramel Sauce
• Using a medium size sauce pan (deep enough to prevent boil over)  melt the butter over medium heat.  
• Add the brown sugar and the remaining ingredients.
• Stir to  blend, try to keep mixture off the sides of the pan. Once the mixture begins to boil, reduce the heat to low.
• Cover the pot and simmer for 5 to 6 minutes, check the pot making sure it will not boil over.
• Keep in mind that the caramel thickens as it cools.

For the Apple Cake

• Preheat the oven to 350 degrees, grease and flour three 8x2 inch round pans
• In a medium bowl, whisk the cake flour, baking powder, baking soda, apple pie spice and salt for 30 seconds. Set aside
• In another bowl, add the buttermilk, oil and vanilla.  Set aside.
• In the bowl of your mixer, add the butter and mix until smooth. Gradually add the sugar and continue to mix on medium speed for 3 to 5 minutes until lightened in color and fluffy. 
• Add the eggs one at a time mixing until the yellow of the yolk disappears.
• With the mixer on low speed, alternately add the flour mixture and buttermilk mixture, beginning and ending with the dry ingredients (3 additions of dry ingredients and 2 of liquid).  After the last addition, mix until the batter is combined and smooth.  Be careful not to over-mix or mix at a high speed. 
• Fold in the apples. 
• Bake at 350 degrees for 20 to 25 minutes or until a toothpick inserted in the center comes out clean or with just a few crumbs attached.  Let cool 5 to 10 minutes and turn out.

Assembling the Cake

• Place the first apple cake layer on the cake plate or pedestal. Spread the top of the cake with a thin layer of caramel. We did not take it all the way to the edge. (We did not use a dam of frosting for this step but if you are worried about the caramel escaping, you can pipe one about ¼ inch from the edge of the cake).
• Sprinkle the caramel-glazed layer with chopped pecans. Then pipe on the cream cheese frosting using a disposable piping bag with the tip snipped away. Lightly spread with an offset spatula. Repeat the steps for the second cake layer. Top with the third cake layer.
• Fill in any gaps between the cake layers with frosting and apply a crumb coat (thin coat) of frosting. At this point I like to chill the cake in the freezer for about 15-20 minutes (or longer in the refrigerator) to firm up before applying the final layer of frosting. Decorate however you like! I used my bench scraper around the sides for a smooth finish, then piped scrollwork with a small round piping tip 3. I added a reverse shell border with a star tip 21, and topped the cake with crushed pecans.