Combine butter and marshmallows and
microwave until smooth, about 1-2 minutes, stirring occasionally. Add peanut
butter and mix well. Add the cereal and combine until well coated. Coat a 13 x
9 x 2-inch pan with spray. Press mixture on pan with waxed paper until well
the chocolate and butter in the microwave, in 15 second increments until you
can whisk it together. When the chocolate is cool to touch, coat the
cereal mixture evenly with the melted chocolate. Refrigerate until chocolate
hardens, about 30 minutes. Cut into squares.