In a large saucepan melt butter over low heat. Add 4 cups marshmallows until completely melted. Remove from heat.
Add Cocoa Rice Krispies cereal and graham cracker pieces to marshmallow mixture until fully coated. Add 1 cup marshmallows to mix, then press into greased 13x9 inch pan with a greased spatula.
Sprinkle remaining marshmallows and chocolate chips on top.
Cool and cut into 2-inch squares.