Cream together: sugar, oil, eggs until light. Add crushed pineapple, and rest of ingredients, except flour which you stir in lastly a little at a time..
Bake in a greased (crisco) and floured, 9x13 inch pan.. (this is such a heavy cake, pan spray won't be enough) Bake at 350* for 40-50 minutes.. let cool completely.
Beat Frosting ingredients together, and spread on cooled cake, and top with chopped walnuts to your taste.. cover and refrigerate for at least 4 hours, or overnight.. (this cake gets more moist and flavorful the longer it sits) ENJOY!!