Preheat oven to 350 degrees.
In a large bowl, combine butter and sugar, beat with an electric mixer at medium speed until creamy. Add eggs, one at a time, beating after each addition. Add vanilla.
In a separate bowl, combine flour, cocoa, and salt, whisk to mix. Gradually add flour mixture to butter mixture.
Spread batter into a lightly greased 13" x 9" baking pan. Bake for 35 to 40 minutes, until a toothpick inserted in center comes. Cool completely in a pan on a wire rack. Spread marshmallow creme over brownies.
Combine peanut butter and chocolate chips in a small microwave-safe bowl. Microwave on high for 60. Stir. Heat in 30 seconds intervals thereafter until melted and smooth.
Stir in crispy rice cereal. Spread crispy cereal mixture over marshmallow layer and chill until firm, about 2 hours. Cut into bars and store in an airtight container.