Preheat oven to 325F. Cream margarine, Crisco and sugar. Add eggs, one at a time; cream. Add coconut and vanilla extract. Add flour and milk alternately. Add baking powder and beat mixture well, Add coconut and mix well. Pour into 10 inch tube baking pan. Bake for 1-1/2 hours. Cool 10 minutes in tube pan on top of wire rack. Loosen cake and turn onto 1 cup cake plate.
In small mixing bowl, put the powdered sugar, mayonnaise and water together. Blend well until sugar is dissolved well. Glaze cake when slightly warm.
Cajun Country -- New Iberia, Louisiana