Dissolve the baking soda in the orange juice and the baking powder in the brandy, then add both to a large mixing bowl.

Add the tahini and sugar, and mix until the sugar is well dissolved. Then add the cinnamon.

Toss the walnuts and cranberries with a little flour, then add them to the mixture along with the remaining flour.

Pour the batter into a nonstick baking pan and bake at 350°F (180°C) for 1 hour.

Let the cake cool, then dust with powdered sugar.