Preheat the oven to 350F. Spray a 9×5 loaf pan with nonstick spray, then flour.
In a large mixing bowl, mash the bananas. Add the brown sugar, oil, vanilla, and pineapple juice, and whisk to incorporate.
Set 3 pineapple rings aside for decorating the top. Chop the remaining pineapple rings into small pieces, and stir into the batter.
Sift in the flour, baking soda, salt, and cinnamon, and use a wooden spoon to mix. Finally, add in the pecan pieces.
Transfer the batter to your prepared pan, and top with the extra pineapple rings and pecans.
Bake for about 45 minutes, then cover with foil and bake for 15-20 minutes longer, until a toothpick inserted in the center comes out with just a couple crumbs.