Preheat oven to 350°. Whisk together flour and next 4 ingredients in a large bowl; add eggs and oil, stirring just until dry ingredients are moistened. Stir in vanilla, pineapple, bananas, and 1 cup chopped toasted pecans. Line the bottom of 3 9-inch round cake pans and grease them well with the cooking spray. Spoon batter into them equally.
Bake at 350° for 25-30 minutes or until a wooden pick inserted in center comes our clean. Cool cake layers in pans on wire racks 10 minutes; remove from pans to wire racks, and cool completely (about 1 hour).
Combine the cream cheese, butter, powdered, sugar, vanilla, and heavy cream (or milk) until smooth.
Place 1 cake layer on a serving platter. Spread 1 cup Cream Cheese Frosting over cake layer. Top with second layer, and spread 1 cup frosting over cake layer. Top with third cake layer, and spread top and sides of cake with remaining frosting. Arrange pecans on the outside of the cake however you like.