Preheat the oven to 350°F (175°C). Grease two 8-inch round cake pans and set aside.
Sift together the flour, baking powder, baking soda, and salt in a large bowl to combine.
In a separate bowl, beat the sugars, oil, eggs, mashed bananas, and vanilla extract until smooth and well combined, about 2-3 minutes.
Add the dry ingredients to the wet mixture gradually, folding gently until just combined; avoid overmixing the batter.
Divide the batter evenly between the prepared cake pans and smooth the tops.
Bake for 25-30 minutes, or until a toothpick inserted into the center comes out clean. The cakes should be golden and spring back slightly when pressed.
While the cakes are baking, toast the walnuts in a dry skillet over medium heat until fragrant and lightly browned, about 3-4 minutes. Let cool and then chop coarsely.
Carefully remove the cakes from the oven and cool completely on a wire rack. Once cooled, slice the caramelized bananas into thin slices.
Whip the heavy cream with powdered sugar until soft peaks form, about 3-4 minutes, ensuring it’s fluffy and smooth.
Spread a layer of whipped cream over the first cake layer, then add some caramelized banana slices and toasted walnuts. Repeat with the second layer.
Decorate the top with remaining whipped cream, caramelized bananas, and a sprinkle of toasted walnuts for extra crunch.
Serve slices of this moist, creamy cake with a spoonful of caramelized banana topping for a cozy, nostalgic flavor.
