01 -
Preheat the oven to 350°F. Line a 9x13 baking dish with parchment paper, set aside.
02 -
In a medium sized bowl, stir together the flour, baking powder, and salt, set aside.
03 -
Place the melted butter into a large bowl with the brown sugar, mashed banana, egg, and vanilla, whisk until smooth.
04 -
Add the flour mixture and stir until combined with no dry patches.
05 -
Spread the batter into the prepared baking dish. Bake for 30-35 minutes until the edges are golden brown and a toothpick inserted into the center comes out clean.
06 -
Place the baking dish on a wire rack to cool completely.
07 -
While the blondies are cooling, make the frosting by placing the cream cheese and butter into a large bowl and whip it until smooth with an electric hand mixer. You can also do this with a stand mixer with the paddle attachment.
08 -
Add the powdered sugar a little at a time until combined, scrape down the sides as needed. Add the vanilla, turn the mixer on to medium speed and whip for 3 minutes until light and fluffy.
09 -
Lift the blondies out of the baking dish using the parchment paper to help. Frost them and cut into bars, serve immediately.