In a large bowl, empty the cereal and the peanuts.

In a saucepan on the stove melt butter, sugar, syrup, and salt. Bring to a boil and boil for 5 minutes stirring constantly. Add the baking soda, and stir, ingredients will foam and become frothy.

Pour the mixture over the cereal and peanuts. Mix quickly but carefully. You don't want to smash all of the cereal. Spread onto a cookie sheet lined with non-stick foil or sprayed with non-stick cooking spray.

Bake at 200 degrees for one hour, turning mix over every 15 minutes.

When the mix has cooled, add the M&M's.