Preheat oven to 170 degrees C. Grease and flour two 20cm round cake tins.
In a medium bowl, cream together the butter, white sugar and brown sugar. Stir in the eggs one at a time beating well after each. Sift together the flour, salt, cinnamon, bicarb soda and baking powder, stir into the creamed mixture. Finally stir in the vanilla, carrots, pineapple and walnuts. Divide batter evenly between the two tins. Don 't worry about filling them too full, as this cake does not rise very much.
Bake for 60 to 75 minutes in the preheated oven. Test for doneness with a toothpick or knife.