Preheat oven to 350 degrees Fahrenheit. Line two baking sheets with parchment paper and set them aside.
In a medium mixing bowl, whisk together flour, baking soda, baking powder, cinnamon, nutmeg, ginger, and salt until combined. Set aside.
In the bowl of a stand mixer fitted with a paddle attachment, beat sugar, oil, and vanilla on medium speed (5-6 on a stand mixer) until combined, about 2-3 minutes. Add eggs one at a time, mixing until combined after each addition. Continue to beat on medium speed until mixture is pale and fluffy, about 3-5 minutes.
Reduce mixer speed to low and slowly add the flour mixture to the oil mixture and mix until no more dry flour is visible. Fold in mashed banana, pineapple, and pecans with a rubber spatula until just combined into the batter.
Using a medium cookie scoop, scoop out batter and level off with a knife. Place batter scoops onto the prepared baking sheets, spacing them about one inch apart. You should get about 28 cakes, depending on the size of your cookie scoop. Bake the cakes in batches in preheated oven for 8-10 minutes or until light golden brown. Cool the cakes on the baking sheet for 5 minutes then transfer to a wire rack to cool completely, about 30 minutes.
While cakes are cooling, prepare the frosting by beating butter, cream cheese, powdered sugar, and vanilla in the bowl of a stand mixer fitted with the whisk attachment until smooth and creamy, about 3-5 minutes. Be sure and scrape down the bowl about halfway through to ensure all ingredients get mixed together. Transfer frosting to a piping bag.
Pipe about 2 tablespoons of frosting onto the flat sides of half of the cooled cakes. Place the remaining cakes on top of the frosting, flat side down, and gently press down to sandwich the frosting in between the cookies. Enjoy!