Preheat oven to 350°F and grease and flour three 9-inch round cake pans.
Whisk together flour, sugar, salt, baking soda, and cinnamon in a large bowl.
Add eggs and vegetable oil, stirring until dry ingredients are just moistened.
Fold in vanilla extract, undrained crushed pineapple, mashed bananas, and toasted pecans.
Divide batter evenly among prepared cake pans and smooth the tops.
Bake for 25–30 minutes until a toothpick inserted in the center comes out clean.
Cool cakes in pans for 10 minutes, then transfer to cooling racks and cool completely for about 1 hour.
Beat cream cheese and butter until smooth using an electric mixer.
Gradually add powdered sugar, then mix in vanilla extract and beat until fluffy.
Place one cake layer on a serving plate and spread frosting evenly over the top.
Add the second layer and frost again.
Place the final layer on top and frost the top and sides of the cake.
Decorate with toasted pecan halves before serving.