It's an unusual and labor-intensive cake. First of all, the dough is rolled out like a cookie. It bakes into a pretty hard disk that will get mildly saturated with dried apples reconstituted with spices and sugar. The apples can't be fresh, and cheating the drying process is not acceptable. Electric fruit dehydrators save the effort of sun-drying apples on the porch or rigging an elaborate clothesline system in the attic—all methods I was told about by people who have seen it done.
One important element of the stack cake is timing. It must be wrapped and left in the refrigerator at least overnight, longer if possible. Whether you wrap it with wax paper and dish towels, aluminum foil, or plastic wrap, one way or another, keep it well covered so the moisture won't escape.
Ingredients
Creaming Ingredients:
Filling:
Instructions
2. Combine the dry ingredients in a bowl and whisk to combine. Set aside.
3. Combine the butter and sugar in the bowl of a standing mixer fitted with the paddle attachment and mix on medium speed until wet and grainy.
4. Add the molasses. Scrape the sides of the bowl with a flexible spatula to get all of the molasses into the mixture.
5. Add the eggs one at a time. Scrape all the way to the bottom of the bowl and mix on low speed.
6. Alternately add the buttermilk and the dry mixture about a quarter at a time. Stop the mixer to scrape the bowl and turn it on again on low speed for about 10 seconds. The mixture should be stiff like a soft cookie dough.
7. Shape the dough into a ball and wrap it in plastic wrap. Refrigerate for 30 minutes.
8. Divide the dough into 6 or 8 equal portions and place each one on a round piece of parchment paper a little larger than a 9-inch cake pan. Roll out the dough to the size of the parchment. Place the cake pan over the disk and trim away the excess around the edge.
9. Leaving the parchment paper underneath, lift the disks onto baking sheets and bake them for approximately 10 minutes, or until the top surface appears dry and a wooden skewer inserted in the center comes out clean.
10. Slide the disks off the baking sheet onto a flat surface to cool.
11. To make the filling, combine all the ingredients in a large, heavy-bottom saucepan and bring to a light simmer. Immediately transfer to the work bowl of a food processor fitted with the steel blade and pulse into a thick paste.
12. To assemble the cake, spread about 1 cup of the filling onto each layer, taking care to center each disk on top of the one beneath it. Repeat until all the layers are used. Do not put apple filling on top of the cake.
13. Wrap the cake well and refrigerate it for up to 24 hours. This gives the apple filling time to work itself into the cake. Dust with confectioners' sugar and serve chilled.
Note: Ideally, you should dry the apples yourself in a fruit-dehydrating machine. If that's not an option, go for store-bought dried apples. Don't cop out and buy applesauce, because the secret to the stack cake is not just what absorbs into the cake, but what doesn't. Jarred applesauce gets lost in the layers, leaving only a soggy stack. Although success isn't guaranteed, you can try to make dried apple slices in the oven. Peel and thinly slice 15 to 20 fresh apples (I like Gala or Cortland). Place them, without overlapping, on a baking sheet lined with parchment paper, and bake in a 225°F oven for up to 4 hours or until dried.
Excerpted from United Cakes of America: Recipes Celebrating Every State by Warren Brown. © 2010 Published by Stewart, Tabori & Chang. All Rights Reserved.

Andrea Reusing is the creator of the restaurant Lantern in Chapel Hill, N.C., and author of the book Cooking in the Moment: A Year of Seasonal Recipes. In this installment of The Key 3, she shares with Lynne Rossetto Kasper the techniques behind three of her favorite recipes: Turnip Soup, Overnight Braised Short Ribs and Tomato Salad.