Mix the warm soy milk, yeast, and one tablespoon of sugar in a bowl (note 1). Set aside for a few minutes until the mixture starts to become frothy.
Add the remaining sugar, melted margarine, orange zest, lemon zest, port wine, and mix.
In a separate bowl, mix the flour, potato starch, fine salt, cinnamon, and turmeric.
Gradually add the dry ingredients to the wet ones, mixing with a spoon, until it’s possible to knead with your hands.
Knead until you get a soft and elastic dough, about 10 minutes (note 2).
Place the dough in a large bowl, cover with a cloth, and let it rise until it triples in size (note 3).
Add the nuts and raisins to the dough, kneading until well incorporated (note 4). Let it rest for 15 minutes.
Shape the dough into a ring, making a hole in the center with your hands, and place it on a baking tray. Put a glass in the center to help the dough maintain its shape, cover with a cloth, and let it rise until it doubles in size.
Remove the glass, decorate the top of the cake with some nuts, and brush with a little margarine.
Bake in the preheated oven at 180°C/356ºF for about 30 minutes or until golden.
After cooling, brush with agave syrup and dust with icing sugar.