Make the cake: Preheat oven to 350 degrees. Generously butter two 9-inch round cake pans or one baking 14-x-9-inch baking pan. Set aside.
- In a large bowl, whisk together dry ingredients. Set aside. In another large bowl, whisk eggs with oil until emulsified. Add vanilla and pineapple and whisk to combine. Stir in bananas and whisk until well incorporated.
- Working in batches, add the dry ingredients to the wet, stirring until just mixed in. Don’t over mix. On the last addition of dry ingredients, add the pecans. The final batter will be very thick.
- Divide batter between the cake pans, and bake until a toothpick inserted in the center comes out clean, 30 to 35 minutes. Because this cake is so moist, a few crumbs may stick to the toothpick. Let the cakes cool in pans for 15 minutes, then transfer to a cooling rack until room temperature.
Make the frosting: While the cake is cooling, make the cream cheese frosting. Using a stand mixer fitted with a paddle attachment, cream butter and cream cheese until smooth and fluffy. Add the confectioners’ sugar, 1 cup at a time, and mix on low speed. Add vanilla and pineapple juice and increase speed to medium until the frosting is smooth and holds its shape.
Assemble: Use a serrated knife to level the cakes if they domed during the bake. On a cake stand, spread a thin layer of the cream cheese frosting and center first cake over it. Frost the top, smoothing over to the sides. Add the next cake and repeat, using remaining frosting to cover the cake’s sides. Top with toasted pecans.