Grease a 9x13" pan with cooking spray; set aside.
Add the Rice Krispies and Special K cereal to a large mixing bowl; set aside.
In a medium-sized microwave-safe bowl, combine the corn syrup, brown sugar and salt.
Microwave on HIGH for 1 1/2 - 2 minutes, stirring every 30 seconds until the brown sugar is dissolved. (You don't want the mixture to boil, so if you start seeing bubbles, take it out of the microwave right away)
Stir in the vanilla and peanut butter until smooth.
Pour over the cereal and stir until almost combined.
Add the chocolate chips and M&M's and mix until well combined.
Pour into prepared 9x13" pan and spread out in an even layer.
Let cool, cut into bars and enjoy!