Ingredients
Method
Place a rack in middle of oven; preheat to 325°. Lightly coat two 8"-diameter cake pans with nonstick vegetable oil spray; line the bottom of each with a parchment paper round. Place 3 large very ripe bananas, peeled, in large bowl; whisk vigorously to smash (some small pieces may remain). Add 2 cups (packed; 400 g) light brown sugar, 1 cup vegetable oil, 1 Tbsp. vanilla bean paste or vanilla extract, 2 tsp. Diamond Crystal or 1¼ tsp. Morton kosher salt, 2 tsp. ground cinnamon, and ½ tsp. freshly grated nutmeg; whisk until smooth with no undissolved lumps of brown sugar, about 2 minutes. Add 3 large eggs and whisk until incorporated. Whisk in 2 tsp. baking powder, then add 2 cups (250 g) all-purpose flour and whisk just until combined. Divide batter evenly between prepared pans.
Bake cakes until tops spring back when gently pressed in the center, 35–40 minutes (tops may feel slightly sticky; cake is very moist, so err on the side of slightly overbaking rather than underbaking). Transfer pans to a wire rack set inside a rimmed baking sheet and let cakes cool in pans 15 minutes. Invert cakes onto rack and peel away parchment; discard. Let cakes cool completely. Using a long serrated knife, slice each cake in half horizontally to make 4 layers total.
Meanwhile, toast 1 cup raw pecans on another rimmed baking sheet until slightly darkened in color and fragrant, 15–18 minutes. Let cool, then finely chop and set aside. Do Ahead: Cakes can be baked 1 day ahead; store loosely wrapped at room temperature. Pecans can be toasted and chopped 4 days ahead; store airtight at room temperature.
Cook zest of 1 lime, one 20-oz. can crushed pineapple, drained, ¾ cup (150 g) granulated sugar, and ½ tsp. Diamond Crystal or ¼ tsp. Morton kosher salt in a medium saucepan over medium heat, stirring often, until pineapple is translucent and mixture is thick with very little to no liquid remaining, 15–18 minutes (some of the pineapple may begin to toast and turn golden). Remove pan from heat and stir in juice of 1 lime. Do Ahead: Jam can be made 4 days ahead. Let cool. Transfer to an airtight container; cover and chill.
Beat 1 lb. cream cheese, room temperature, in the bowl of a stand mixer fitted with the whisk attachment on medium speed until very smooth and fluffy, 8–10 minutes. Add 3 cups heavy cream, ¾ cup (150 g) granulated sugar, 2 tsp. vanilla bean paste or vanilla extract, and 1½ tsp. Diamond Crystal or ¾ tsp. Morton kosher salt and beat, starting on low speed and gradually increasing to medium and scraping down sides of bowl as needed, until firm peaks form, about 5 minutes. Chill frosting at least 15 minutes and up to 1 hour.
Set about 2 Tbsp. pineapple jam and about ½ cup frosting aside for final decorations on cake.
Place 1 bottom cake layer, cut side up, on a cake stand or large plate. Spoon ⅔ cup frosting over; using spoon or an offset spatula, smooth frosting to edges of cake to create an even layer. Spoon small dollops of jam over frosting (use about a third of the jam). Place another cake layer on top and spread another ⅔ cup frosting over. Dollop half of remaining jam over frosting. Repeat process one more time, using remaining jam. Place final cake layer on top and dollop about 1 cup frosting over; smooth across top and down sides of cake to create a very thin layer. You want to fill in any gaps, adhere any crumbs to cake, and seal in fillings (this is called a crumb coat); chill cake 20 minutes.
Smooth remaining frosting over top and down sides of chilled cake to cover completely. Place reserved frosting in pastry bag fitted with ribbon or star tip. Pipe frosting over surface as desired. Place dollops of pineapple jam around as desired. Press pecans along the bottom of the sides of the cake, working around the cake in batches and gently pushing them in with a bench scraper or the back of a large knife to adhere. Chill cake at least 30 minutes before serving. Do Ahead: Cake can be made 1 day ahead. Cover with a cake dome or large bowl and keep chilled.