Preheat oven to 180 degrees C. Grease and flour a ring tin.
Sift together flour, cinnamon, salt, baking powder and bicarb soda on to a piece of waxed paper.
In a large bowl, beat eggs and sugar until light coloured. Mix in oil. Add sifted ingredients to egg mixture and beat for 2 minutes. Stir in pineapple, chopped walnuts, vanilla and zucchini. Mix thoroughly. Pour batter into prepared pan.
Bake for 80 minutes, or until a skewer inserted in the centre of the cake comes out clean. Cool for 30 minutes.
To make glaze: In a small bowl, combine the icing sugar and the milk. When cake has cooled, drizzle the glaze over cake.