Preheat oven to 350°F (180°C).

In a large bowl, whisk together flour, sugars, cinnamon, baking soda, salt, and nutmeg.

In a medium bowl, whisk together pineapple, banana, oil, egg, and vanilla. Add pineapple mixture to flour mixture, whisking just until combined. Fold in pecans.

Spray a 6-cup Charlotte pan with baking spray with flour. Pour batter into prepared pan. Tap pan on a kitchen towel-lined counter several times to settle batter and release air bubbles.

Bake until a wooden pick inserted in center comes out clean, 45 to 50 minutes. Let cool in pan for 10 minutes. Remove from pan, and let cool completely on a wire rack.

Place Cream Cheese Frosting in a pastry bag fitted with a ½-inch French star piping tip (Ateco #865). Pipe on top of cake as desired. Garnish with pecans, if desired. Refrigerate until frosting is set, 15 to 20 minutes, if desired. Cover and refrigerate for up to 3 days.