Generously butter the sides and bottom of a 10 inch springform pan. Cut a piece of parchment paper to fit the bottom and place in the pan. [optional - just a bit of extra insurance against sticking]
Combine the dry ingredients in a medium bowl, and whisk together thoroughly.
Combine the apples, apple sauce and bourbon in a smaller bowl.
In the bowl of a stand mixer [or use a hand mixer and a large bowl], cream the butter and sugar until light.
Beat in the eggs, one at a time.
Beat in the vanilla, and then scrape down the sides of the bowl.
Beat in the remaining ingredients, alternating in thirds, between the dry ingredients and the apple mixture, You want a smooth batter, but don't over-mix, because the cake won't rise as well.
Scrape the batter into the prepared pan, and bake on the middle rack of the 350° oven, for 50 minutes to an hour, turning the pan twice during baking time.
The cake is done when a toothpick inserted near the center comes out clean, with maybe just a few crumbs sticking, but no wet batter.
Remove from the oven when done, and allow to sit for 5 minutes. Remove the sides of the pan and set the cake on a cooling rack.
Can be served warm, with toppings of your choice - powdered sugar, whipped cream, warm applesauce, vanilla ice cream, or any combination of the above.
Store covered in the refrigerator for up to a week. Leaving this out on the counter isn't recommended, because of the apples.
Notes
A good dessert for a crowd, this makes 10 to 12 servings.