spray 9x13" pan with non-stick cooking spray. also spray the bottom of a metal spatula with non-stick cooking spray and set aside.

in stock pot over medium heat, melt butter, peanut butter, marshmallows, and corn syrup. stir until smooth.

when smooth, remove from heat. add rice krispies. let cool 5 minutes.

stir in chocolate chips.

using prepared metal spatula, press mixture into prepared pan. chill 15 minutes, then keep at room temperature, covered.