Preheat your oven to 350°F (175°C) and line a cupcake pan with paper liners.

In a medium bowl, whisk together the flour, baking powder, baking soda, and salt. Set aside.

In a large bowl, cream the softened butter and sugar using a hand mixer until light and fluffy (about 3-4 minutes).

Beat in the eggs one at a time, ensuring they're fully incorporated before adding the mashed bananas and vanilla extract.

Gradually add the flour mixture to the banana mixture, alternating with the sour cream, starting and ending with the flour. Mix until just combined; do not overmix.

Fill each cupcake liner about 2/3 full with batter. Bake in the preheated oven for 18 to 20 minutes or until a toothpick inserted into the center comes out clean.

Remove the cupcakes from the oven and allow them to cool in the pan for 5 minutes before transferring them to a wire rack to cool completely.

In a mixing bowl, beat the softened cream cheese until smooth. Gradually add the powdered sugar and vanilla extract, mixing until fluffy.

Once the cupcakes are completely cool, frost each with the cream cheese mixture using a spatula or piping bag.

These delightful cupcakes are best enjoyed fresh, but they can be stored for later.