In a large microwavable bowl, mix the cereals, pretzels & peanuts; set aside.

In a 2-cup microwavable measuring cup, microwave brown sugar, butter and corn syrup on High about 2 minutes, stirring after 1 minute, until melted and smooth.

Stir in baking soda until dissolved.

Pour brown sugar, butter, corn syrup mixture over the cereal mixture, stirring until evenly coated.

Microwave uncovered on High 1 to 2 minutes, stirring and scraping bowl every 30 seconds, just until cereal begins to brown.

Cool 5 minutes; stir in M&M candies.

Spread on waxed paper to cool; break into bite-sized pieces.

Store in an airtight container.