Preheat the oven to 350 F. Grease and line the bottoms of two 9-inch round cake pans with parchment paper. Whisk together the gluten free 1-to-1 baking flour, baking powder, baking soda, cinnamon, and salt in a medium bowl.
In a large bowl, whisk together the granulated sugar, vegetable oil, eggs, and vanilla extract until smooth. Stir in the mashed bananas and drained crushed pineapple. Add the flour mixture and stir until just combined. Fold in the chopped pecans.
Divide the batter evenly between the prepared pans. Bake for 28 to 33 minutes until a toothpick inserted in the center comes out clean. Let cool in the pans for 10 minutes, then turn out onto wire racks and cool completely.
For the frosting, beat the cream cheese and butter together on medium speed until smooth. Add the powdered sugar one cup at a time, beating on low after each addition. Add the vanilla extract and beat on medium-high speed for about 1 minute until light and fluffy.
Place one cake layer on a serving plate. Spread a thick layer of frosting on top. Place the second layer on top and frost the top and sides with the remaining frosting. Sprinkle the chopped pecans over the top for garnish.