"These peanut butter and banana cookies are fit for the king."
Preheat oven to 350 degrees F (175 degrees C). Lightly grease a baking sheet.
Stir together the butter, brown sugar, white sugar, peanut butter, and vanilla in a bowl. Mash the bananas into the mixture until there are few lumps. Sift together the flour and baking powder in a separate bowl; add to the banana mixture and stir until thoroughly incorporated. Drop rounded tablespoons of mixture onto the prepared baking sheet.
Bake in preheated oven until lightly brown and firm, about 10 minutes.