Preheat your oven to 350°F (175°C). Lightly grease and flour a 9x13 inch baking pan.

In a large bowl, whisk together the flour, baking powder, baking soda, and salt.

In a separate bowl, beat the softened butter and granulated sugar until light and fluffy (about 5 minutes).

Stir in the mashed bananas, milk, and vanilla extract into the butter-sugar mixture. Mix well until fully combined.

Gradually add the dry ingredients to the wet mixture, stirring until just combined (avoid overmixing!).

Pour the batter into the prepared baking pan. Bake in the preheated oven for 30-35 minutes or until a toothpick inserted in the center comes out clean.

In a large bowl, whisk together the instant pudding mix and milk until it thickens. Stir in 1 teaspoon of vanilla extract.

Once the cake has cooled, slice it in half horizontally. Spread half of the banana pudding mixture over the bottom layer, place the other half of the cake on top, and then spread the remaining pudding on top of the second layer.

Decorate with a generous layer of whipped cream and fresh banana slices on top.

Refrigerate for at least 1 hour before serving to let the flavors meld beautifully.