In a large bowl, cream butter and sugar until light and fluffy, 5-7 minutes. Add eggs, 1 at a time, beating well after each addition. Beat in vanilla. In a small bowl, combine bananas and pineapple., Combine the flour, baking soda, cinnamon and salt; add to the creamed mixture alternately with banana mixture, beating well after each addition. Fold in coconut and walnuts., Fill 24 paper-lined muffin cups about two-thirds full. Bake at 350° until a toothpick inserted in the center comes out clean, 20-25 minutes. Cool the cupcakes for 10 minutes before removing from pans to wire racks to cool completely., In a small bowl, beat cream cheese and butter until fluffy. Add confectioners’ sugar and vanilla; beat until smooth. Frost cupcakes.