1.Place apples and water in a large saucepan; cover surface with a round of baking paper, then a small plate to weight down. Bring to the boil over high heat. Reduce heat; simmer, for 20 minutes or until apple is soft. Drain. Cool. Blend or process apple, in batches, until smooth; transfer to a large bowl. Stir in brown sugar and spices.
2.Preheat oven to 180°C. Grease and line two oven trays with baking paper.
3.Beat butter, caster sugar and extract in a small bowl with an electric mixer until pale and fluffy. Beat in eggs, one at a time, until just combined. Transfer mixture to a large bowl. Sift flours, soda and salt into another large bowl. Stir flour mixture into creamed mixture alternately with buttermilk, in three batches, until combined (mixture will be stiff; you may need to finish combining with your hands). Knead dough on a floured surface until smooth and combined.
4.Divide dough into eight equal portions. Roll one portion of dough between sheets of baking paper into a 23cm round. Using a 22cm (9-inch) plate or cake pan as a guide, cut round from dough. Transfer to one tray. Repeat with another portion of dough and second tray.
5.Bake for 12 minutes, swapping trays from top to bottom halfway through cooking time or until golden. Stand dough on trays for 5 minutes before transferring to wire racks to cool. Repeat steps 4 and 5 with remaining dough portions, in batches, to make eight rounds in total.
6.Place a cake round on a platter or cake stand; spread with a slightly rounded ½ cup of apple filling. Repeat layering with remaining cake rounds and apple filling, finishing with a cake round. Cover cake with plastic wrap; refrigerate overnight. Just before serving, dust cake with icing sugar; decorate with cinnamon sticks.
This cake needs to be made at least a day ahead. Or, up to 2 days ahead; store, covered, in the refrigerator.Note