1Preheat oven to 350 degrees F (175 degrees C). Grease and flour a 9x13 inch pan.
2In a medium bowl, stir together the flour, sugar and baking soda. Add eggs and mix until well blended. Fold in the pineapple, coconut and walnuts. Pour into the prepared pan.
3Bake for 30 to 35 minutes in the preheated oven. In a medium bowl, beat together the butter and cream cheese. Mix in the confectioners' sugar until smooth. Spread frosting over cooled cake.