In a sauce pan over medium heat, combine the corn syrup and sugar. Stir over the heat until the sugar dissolves and the mixture comes just to a boil.
Add in the vanilla and stir.
Remove the pan from the heat and add in the peanut butter, stir until smooth.
Place the crisp rice cereal in a large mixing bowl. Pour the peanut butter mixture over the cereal and stir until it is all covered.
Press the cereal and peanut butter mixture into a greased 13 x 9 x 2 inch pan.
Place the chocolate chips into a microwave safe bowl and cook for one minute. Stir and cook for 30 seconds more if needed until smooth and melted. Spread the melted chocolate over the top of the rice krispie bars.
Allow to cool and slice into squares to serve.
These are best served fresh, but if you do happened to have leftovers, store in an air tight container and enjoy within 2 days.