Place rice Crispy cereal in a large mixing bowl and set aside. Grease a 9x13 size baking pan and set aside also.
In a large sauce pan over medium heat combine Karo syrup, sugar and salt. Stir until all sugar is dissolved and bring to a boil (stirring constantly). Reduce heat and gently boil for 1 minute longer.
Remove from the heat and add peanut butter, chocolate chips, and vanilla. Stir until melted and smooth. Pour over the rice crispies and mix until well coated. Place mixture into your greased 9x13 pan and pat down evenly. Let cool for 15 mins. sprinkle pieces ofchopped Reese's cups on top and slightly press down. Cool completely for an hour and then cut into bars.