Preheat oven to 350°F. Grease three 6-inch pans with shortening and then flour. Line bottoms with parchment paper.
In a large bowl mix all dry ingredients together.
Add in the canola, eggs, banana, crushed pineapple, and vanilla. Stir until combined. Mix in the pecans.
Equally divide batter between the 3 pans and bake for 35-40 minutes until toothpick comes out mostly clean. (A few crumbs should stick to the toothpick! Start checking the cake at 25 minutes and rotate pans if needed.)
Place the cake pans on a cooling rack for 5 minutes and then remove cakes from pans. Allow to cool completely.
If needed, cut the tops off the cakes if they aren’t flat. Wrap each layer in plastic wrap and place in the freezer.
Frosting
In the bowl of an electric mixer fitted with the paddle attachment, beat butter and cream cheese together until smooth. Add the vanilla and powdered sugar and begin beating on low. Increase speed and beat for about 3 minutes until smooth and fluffy. To get air pockets out, turn down to the stir setting and let it run for 3-5 minutes. Apply frosting to cooled cake.
Assembling the Cake
Assemble cake by placing one layer on a cake stand. Apply one even layer of frosting and repeat with remaining cake layers. Apply a thin crumb coat and chill for 15-30 minutes.
Frost the sides (the final, beauty coat of frosting) and top of the cake. Sprinkle the top with toasted pecans and press some into the sides of the cake.
