Preheat the oven to 325°F/160°C. Combine the oil, brandy, orange zest and juice, and sugar in a large bowl and beat well. Sift the flour with the baking powder and soda into a second bowl. Gradually add the flour to the liquid mixture and knead well for 5 to 6 minutes. Break off small pieces of dough and form small rounds or oval shapes about 3-inches/7-cm long. Place them on an un-greased baking sheet or two if necessary. Once you’ve finished, gently press each melomakarono against the surface of a grater in order to leave a decorative pattern on each one and return it to the sheet. Bake the melomakarona until golden, about 30 minutes. Remove them from the oven and let cool on the baking sheet. For the honey syrup: Combine the honey, sugar, and water in a medium saucepan and bring to a boil. Skim the foam off the top, add the cinnamon stick, reduce the heat, and simmer until the syrup is thick, 10 minutes. Arrange the cold melomakarona on a platter and pour the hot syrup over them. Sprinkle with the crushed walnuts and a little powdered cinnamon.