First Step: Prepare Oven and Pans
Preheat your oven to 300°F (150°C). Toast chopped pecans on a lined baking sheet for 7 to 8 minutes until fragrant; let cool for 10 to 15 minutes. Increase oven temperature to 350°F (175°C) before baking. Grease three 8 or 9-inch cake pans, line with parchment paper rounds, and grease the parchment to prevent sticking.

Second Step: Mix Dry Ingredients
In a large bowl, whisk together the all-purpose flour, baking powder, baking soda, ground cinnamon, allspice (if using), and salt. Make sure the dry ingredients are evenly distributed for consistent texture.

Third Step: Combine Wet Ingredients
In a separate bowl, whisk mashed ripe bananas, crushed pineapple (with juice), eggs, vegetable oil, brown sugar, granulated sugar, and pure vanilla extract until smooth and fully blended.

Fourth Step: Blend Wet and Dry Ingredients
Pour the wet ingredients into the dry ingredients bowl. Gently fold together until just combined to avoid overmixing, which can make the cake dense or tough. Fold in 1 ½ cups toasted pecans, reserving some for garnish.

Fifth Step: Bake the Cake Layers
Divide batter evenly among the three prepared pans. Bake for 26 to 32 minutes. Rotate pans halfway through baking for even cooking. Test doneness by inserting a toothpick in the center it should come out clean or with moist crumbs.

Final Step: Cool, Frost, and Assemble
Cool cakes completely in pans on wire racks. Level tops with a serrated knife for even layering. For the frosting, beat full-fat cream cheese and softened unsalted butter on medium-high speed until smooth. Gradually add confectioners’ sugar, vanilla extract, and a pinch of salt. Beat on low for 30 seconds, then high for 3 minutes until light and fluffy. Assemble layers by spreading frosting between each. Frost the top and sides, decorate with reserved toasted pecans. Refrigerate assembled cake 15 to 20 minutes before slicing to set the frosting.