1To make the cake, position racks in the center and bottom third of the oven and preheat to 350^. Lightly butter two 9" round cake pans, sprinkle evenly with flour and tap out the excess.
2Sift the flour, sugar, baking soda, cinnamon and salt into a bowl. In another bowl, stir or whisk the bananas, pineapple, oil, eggs and vanilla until combined. DO NOT USE AN ELECTRIC MIXER. Pour into the dry mixture and fold together with a large spatula just until smooth. DO NOT BEAT. Fold in the pecans. Spread evenly into the pans.
3Bake until the cake springs back when pressed in the center, 30 to 35 minutes. Transfer the cakes to wire racks and cool for 10 minutes. Invert the cakes onto the racks. Turn right side up and cool completely.
4To make the icing: Using an electric mixer on high speed, beat the cream cheese and butter in a large bowl until combined. On low speed, gradually beat in the sugar, then the vanilla, to make a smooth icing.
5Place 1 cake layer, upside down on a serving platter. Spread with about 2/3 cup of the icing. Top with the second layer, right side up. Spread the remaining icing over the top and sides of the cake. The cake can be prepared up to 1 day ahead and stored, uncovered in the refrigerator. Let stand at room temp. 1 hour before serving.