Combine together the oats and rice cereal in a large bowl. You can use a whisk to help you fully incorporate the ingredients.
Line a rimmed baking sheet with parchment paper and then set the sheet aside as you work. Also, prepare a second sheet of parchment paper that will be used to roll out the bars later on.
In a medium saucepan on medium heat, combine together the brown sugar, corn syrup, oil, and vanilla extract. Use a whisk to stir the mixture constantly as you bring it to a boil. Once it starts to boil, let it boil for 45 second before removing the saucepan from the heat. Carefully stir in the peanut butter with the warm ingredients in the saucepan. Once the ingredients in the saucepan are combined and smooth, carefully pour about half over the oats and cereal in the large bowl. Give the ingredients a quick stir and then add the remaining warm ingredients. Use a spatula to mix the ingredients together until fully incorporated and the cereal and oats are fully covered with the warm ingredients.
Carefully transfer the ingredients to the prepared baking sheet and use your spatula to evenly spread the ingredients over the sheet.
Place the remaining piece of parchment paper over the ingredients on the baking sheet and then use a rolling pin to help press the ingredients into place so that the sheet is evenly covered with the mixture which is at equal thickness as well.
Next, remove the parchment paper so that you can sprinkle your peanut butter chips across the pressed in ingredients evenly and then cover with the parchment paper again to press down into the bars slightly.
Let the bars sit on the baking sheet until set, preferably with the parchment on top and refrigerated, (about an hour). When you are ready to cut the bars into servings, use the parchment paper lining the baking sheet to life the bars, place the bars on the sheet on to a cutting board, and slice the bars into servings.