Place 2 cups pecan HALVES on a baking sheet and toast in a preheated 350-degree oven for about 8-10 minutes. When cool, finely chop 1-1/2 cups of the pecans, reserving 1/2 cup pecan HALVES. Set aside.
FOR CAKE: In a large bowl, whisk together the flour, sugar, baking powder, salt and cinnamon.
In another large bowl, mix the eggs, oil, vanilla, pineapple, bananas, and 1 cup of the chopped pecans. Add this mixture to the flour mixture and stir until combined thoroughly.
Evenly divide the batter between two round cake pans that have been buttered or sprayed with cooking spray and lined with parchment paper.
Bake in a 350-degree oven on the center rack for 25 to 30 minutes, or until a toothpick inserted near the center comes out clean.
Remove from oven and let cool on a wire rack for 10 minutes. Then invert the cake layers onto the rack and cool completely.
FOR FROSTING: In a large bowl, with an electric mixer, beat the cream cheese on low speed until completely smooth, with no lumps. Gradually add the sugar and beat on low speed until smooth. Add the vanilla and 1/2 cup chopped pecans. Mix thoroughly.
ASSEMBLY: Place one cake layer top-side down on a serving plate. Frost the top of layer with 1/3 of the frosting. Place the other layer top-side up on top of the frosted bottom layer. Spread top and sides with the remaining frosting. Garnish with remaining pecan halves.