Lightly coat a 13x9-inch pan with non-stick spray.
In a large stock pot, combine sugar and light corn syrup.
Cook over medium heat, stirring frequently, until sugar is dissolved and mixture just bubbles.
Remove from heat.
Add vanilla and peanut butter, stirring until melted and smooth.
Add Rice Krispies and stir until well-coated. The mixture will start to set fast, so stir quickly!
Press mixture evenly into prepared pan.
In a medium saucepan over low heat, combine white chocolate chips, peanut butter chips, and shortening, stirring until melted and smooth. Take your time with this and have patience – don’t use anything but low heat or you’ll risking scorching the chips!
Remove from heat and spread over Rice Krispies mixture.