Place A Rack In The Center Of The Oven, And Preheat The Oven To 350°F.
Grease And Flour Three 9″ Round Cake Pans.
Shake Out The Excess Flour, And Set The Pans Aside.
Place The Flour, Sugar, Cinnamon, Baking Soda, And Salt In A Large Bowl, And Whisk To Combine Well.
Add The Eggs, Oil, And Vanilla, And Blend With A Wooden Spoon Or An Electric Mixer On Low Speed.
Increase The Speed To Medium And Blend Until Well Combined, 1 Minute.
Or Stir More Briskly Until Well Combined.
Fold In The Pineapple, Pecans, If Desired, And The Bananas.
Divide The Batter Between The Prepared Pans, And Place The Pans In The Oven.
Bake Until The Cake Just Pulls Away From The Edges Of The Pans, 18 To 22 Minutes.
Remove To Wire Racks To Cool For 10 Minutes.
Run A Knife Around The Edges Of The Pans, And Give Them A Gentle Shake To Loosen The Cakes.
Invert The Cakes Once And Then Again Onto The Racks.
Let The Layers Cool To Room Temperature, At Least 30 Minutes.
Meanwhile, Prepare The Frosting.
If Using The Pecans As A Garnish, Toast Them In A 350°F Oven For 4 To 5 Minutes.
To Assemble The Cake, Place 1 Layer On A Serving Plate.
Spread With About ⅔ Cup Of Frosting.
Top With A Second Layer And Repeat With The Frosting.
Top With The Third Layer And Frost The Top And Sides Of The Cake With Smooth Strokes.
Garnish The Top Of The Cake With Pecans.
Slice And Serve.
Or Chill For 1 Hour Uncovered For Easier Slicing.
