Preheat the oven to 350 degrees. Line two cookie sheets with parchment paper.
In a bowl, add the banana muffin mix, bananas, egg, yogurt, and oil. Mix with an electric mixer until smooth.
Place the batter in the freezer for 20 minutes.
Remove from the freezer and use an ice cream scoop to scoop equal-sized cookies (I like a 2 tbsp scoop). Place them on the cookie sheets, keeping 2” apart for baking, as they will spread.
Bake for 8-12 minutes, until the edges are lightly golden brown. Cool completely.
Once cooled, frost the cookies with cream cheese frosting and sprinkle the chopped walnuts on top. Enjoy!
