Whisk the oil, eggs, and vanilla in a medium bowl. Add to the flour mixture, and beat on low until combined. Batter will be very thick, almost the consistency of taffy.
1 cup canola oil, 3 large eggs, 1 Tablespoon vanilla extract
With mixer on low, add in the pineapple (with the juice), pecans, and bananas. Increase speed to medium until well combined.
Divide the batter evenly among the prepared pans and bake until a toothpick inserted in the center comes out clean, 25 to 30 minutes. Cool the cakes in the pans for 10 minutes, then turn out onto racks to cool completely.
For the Frosting
With a mixer at medium-high speed, beat the butter until creamy. Reduce mixer speed to low and slowly add the sifted powdered sugar. Increase speed and beat until fluffy, about 2 minutes. Add the cream cheese, one piece at a time, and beat until smooth. Beat in the vanilla and salt.
2 sticks unsalted butter, 16 ounces powdered sugar, 16 ounces cream cheese, 1 1/2 teaspoons vanilla extract, Pinch of salt
Spread about 1 1/2 cups of the frosting on one cake layer. Top with a second cake layer and another 1 1/2 cups frosting. Top with the final cake layer and spread the top and sides of the cake with the remaining frosting.
Ripe bananas are essential. Bright yellow with a few brown spots are ideal, green tips on bananas mean they are underripe.
Don't drain your crushed pineapple! Those juices keep the cake nice and moisture-rich (and of course adds flavor).
I always, always recommend using a kitchen scale to measure your ingredients. Especially when it comes to measuring flour. Too much flour can leave you with a dry, dense cake instead of a tender, moist one. If you do not own a scale, use the scoop and sweet method. Scoop flour with a spoon into a measuring cup until overflowing. Gently level off the top with the back end of a butter knife. Do not pack your flour in or scoop directly from the bag with the measuring cup to avoid overmeasuring.