Apple Jack Stack Cake

Name: Apple Jack Stack Cake
Ingredients: 3 pounds assorted apples, peeled and cut into 1/2-inch wedges; 1/2 cup brown sugar; 1 cup apple cider; 1/4 cup applejack, apple brandy, or bourbon; 1 1/2 cups apple butter; 5 cups all-purpose flour; 1 teaspoon baking powder; 1 teaspoon baking soda; 1/4 teaspoon kosher salt; 1/3 cup buttermilk; 1 teaspoon vanilla extract; 3/4 cup (1 1/2 sticks) unsalted butter; 2 cups granulated sugar; 1/4 cup molasses; 2 large eggs; 1 cup dark brown sugar; 1/4 cup reserved apple cider mixture (from the filling); 1 tablespoon molasses; 2 tablespoons unsalted butter