Peanut Butter Treats™ give classic Rice Krispies Treats® extra nutty flavor with peanut butter. This snack or dessert uses Rice Krispies cereal, butter, marshmallows, and peanut butter. Melt, stir, and press the mixture into a 13 x 9 x 2-inch pan. Cut into 2-inch squares and serve the same day. You can also use the microwave to heat the butter and marshmallows for 3 minutes, stirring after 2 minutes.