Butter/grease a 9x13 inch baking pan.
Add 5 cups marshmallows, milk chocolate, butter and corn syrup in a large sauce pan.
Melt the mixture together over low heat while gently stirring with a rubber spatula.
Once melted remove from the heat and immediately stir in the cereal with the remaining cup of marshmallows. It will be very sticky.
Spoon the batter into the prepared pan and flatten down using the back of your spatula.
Allow to harden at room temperature for 60 minutes before cutting into squares.
