Preheat oven to 170°C/340°F. Place the shelf in the lowest part of the oven.
Grease an 11” cake pan with butter, then line with parchment/baking paper. It's best to use a cake pan with a loose base, if possible.
Whisk the flour, baking powder, and salt in a large bowl. Set aside.
Beat the butter and sugar for a few minutes until creamy and well combined on high speed on a stand Mixer fitted with a whisk attachment, or a hand beater.Add the cinnamon, clove, vanilla extract, and orange juice and beat to combine. Add the eggs one at a time, wait for one to be incorporated into the batter and then add the next one.
Using a separate mixer bowl and whisk, beat the egg whites on medium speed until tripled in volume and white with soft peaks. Set the bowl aside.
Mix the orange juice with the baking soda.
Using the mixer bowl with the batter, lower the speed to the minimum and add the orange juice.
Start adding the flour, milk and brandy. Alternate between them, one part flour, milk, another part flour, then the brandy, and gradually add the rest of the flour. Beating at low speed, add the crushed walnuts.
Remove bowl from mixer and start folding in the egg whites with a spatula, one heaping tablespoon at a time. Be gentle and don't rush this part.Throw into the batter the aluminum foil-wrapped coin. Pour the batter into the prepared baking pan.Bake for 50 minutes to an hour. Insert a cake tester and if it comes out clean the cake is ready. Allow the cake to cool for 15 minutes. Remove the parchment and place the cake on a cake stand or platter. When the cake is completely cool, sprinkle powdered sugar on top and decorate with dried fruit, orange slices, pomegranate seeds if desired, or leave it as is. Traditionally, cut the cake right after New Year's Eve. Whoever gets the coin will have great luck for the whole year!