Preheat oven to 350°F. Make sure you position racks in the center and bottom third of the oven.
Lightly butter three 9-inch round cake pans, sprinkle evenly with flour and tap out the excess. Then line the bottom of each cake pan with rounds of parchment paper.
Sift the flour, baking soda, cinnamon, and salt into a bowl. Set aside until needed.
Place 1 cup of finely diced fresh pineapple in a food processor and pulse until crushed. Do not over-pulse.**You can also use a potato masher to crush the pineapple.
In another bowl, combine the granulated and brown sugar, mix until fully combined.
Add the eggs to the sugar mixture, whisking by hand until the mixture is smooth.
Add the oil and vanilla into the sugar mixture, blending well with a wire whisk.
Add the flour mixture to the wet ingredients and mix with a spoon by hand until the mixture fully combined. Do Not Overmix!
Add the mashed bananas, crushed pineapple (and juice), and chopped pecans to the batter. Mix until just combined.
Divide the batter evenly between 3 prepared pans.
*Tap the pans on the counter to release any air bubbles in the batter.
Place the layers on the center rack of a preheated 350 -degree oven and bake for 25-30 minutes, until the center of cakes springs back when pressed.
Transfer the cakes to wire racks and cool for 10 minutes. After cooling invert the cakes onto the racks (remove the parchment paper) and turn cakes right side up and allow to cool completely before frosting.