Preheat your oven to 350°F (175°C) and grease two 9-inch round cake pans.
In a large mixing bowl, cream together the softened butter and sugar until light and fluffy.
Add the eggs one at a time, mixing well after each addition.
Stir in the vanilla extract and mix until combined.
In another bowl, whisk together the flour and baking powder.
Gradually add the dry ingredients to the wet ingredients, alternating with the milk.
Once fully combined, pour the batter evenly into the prepared pans.
Bake for 25-30 minutes or until a toothpick inserted in the center comes out clean.
Allow cakes to cool in the pans for 10 minutes, then transfer to a wire rack to cool completely.
Layer one cake on a serving plate, spread banana pudding over it, add banana slices, then top with the second cake.
Frost the top and sides with whipped cream, and garnish with vanilla wafers and additional banana slices.