For the apple filling:
- 1 pound dried apples, chopped (4 to 5 packed cups)
- 1 cup packed dark brown sugar
- 1 tsp ground cinnamon
- 1 tsp vanilla
- 1 tsp ground ginger
- 4 cups water
For the cake layers:
- 5 cups all-purpose flour
- 1 tsp baking soda
- 1 tsp baking powder
- 1 tsp ground cinnamon
- 3/4 tsp salt
- 3/4 cup (1 1/2 sticks) unsalted butter, at room temperature
- 1 cup granulated sugar
- 2 large eggs
- 1 cup dark molasses
- 1 cup full-fat buttermilk
- Powdered sugar, for serving (optional)
- Place all the ingredients for the apple filling in a large, heavy-bottomed pot, such as a Dutch oven. Add the water and bring to a boil. Lower heat, cover with lid and simmer, stirring occasionally until the apples are softened, about 25-30 minutes.
- Remove the pan from the heat and set aside to cool while you prepare the cake batter.
- Whisk the flour, baking powder, baking soda, cinnamon, and salt together in a large bowl; set aside.
- Place the butter and sugar in a stand mixer fitted with a paddle attachment using the large bowl. Beat on medium-high speed until light and fluffy, about 3 minutes.
- Add the eggs one at a time, followed by the molasses. Beat until fully combined and lightened in color, about 2 minutes more. Add about 1/3 of the flour mixture to the sugar & butter on low speed, and mix until all the flour has been incorporated. Slowly pour in 1/2 of the buttermilk and mix until fully combined. Repeat stopping the mixer and scraping, mixing in another 1/3 of the flour mixture, then the remaining buttermilk, and finally the remaining flour.
- Cover and refrigerate for 30 minutes.
- While the cake batter is cooling, transfer the cooked and cooled apple filling into in a food processor fitted with the blade attachment or a blender.
- Process or blend into a thick paste, about 2 minutes. Some small lumps are okay, but the paste should be fairly smooth.
- Preheat oven to 350°F. Use a 9-inch round cake pan to trace a circle onto 6 pieces of parchment paper with a pencil. Flip the parchment papers over so that the pencil mark is on the underside.
- Divide the chilled batter into (6) 1 cup portions. Place 1 portion onto the center of each parchment circle. Use an offset spatula to spread the batter into a thin, even disk about the size of the circle. When you have 2 cake layers spread out, move them to a baking sheet on the center oven rack. Bake 2 layers at a time until dry and set about 10 minutes. While each pair of layers bake, spread out another 2 layers, and repeat baking and spreading until all 6 layers are baked.
- Carefully slide the baked cake layers off their baking sheets by the parchment paper as they come out of the oven. Cool on a wire cooling rack for about 10 minutes.
- Remove 1 cake layer from the parchment and place on a cake plate or serving plate. Spread about 1 cup of the apple filling evenly on the cake. Stack another cake layer on top of the filling, making sure you center it. Repeat with filling and stacking the cake until all the cake layers are used. Do not put apple filling on top of the cake.
- Tightly wrap the stacked cake in plastic wrap and refrigerate for 24 to 48 hours before serving.
- Unwrap the cake and garnish with powdered sugar, if desired, before slicing and serving.