In a large bowl, using a hand mixer, blend together the butter, egg and peanut butter until smooth and creamy.
In a separate bowl, stir together the chocolate chip cookie mix, oatmeal, and cereal. With the mixer on medium-low speed, add the dry mixture to the wet ingredients and beat until a dough forms.
Gather the dough into a round disc and wrap in plastic. Chill for 20 minutes, or until firm. Preheat oven to 350 degrees, and line two baking sheets with parchment paper. Remove dough from refrigerator and roll into teaspoon sized balls, placing each on the baking sheet. Bake for 8-10 minutes, until the edges of the cookies begin to turn golden. Cool on a wire rack.