Prepare an 9×9 inch square pan with parchment paper
In a large saucepan, melt the butter completely
Once the butter is melted, add in mini marshmallows and peanut butter; stir until completely melted
Remove the saucepan from the heat and stir in the Rice Krispie cereal into the marshmallow and peanut butter mixture and mix until fully coated
Pour the mixture into the prepared pan and using another sheet of parchment paper, press the rice krispie treats down until they are flat and even in the pan
While the Peanut Butter Rice Krispie Treats are cooling, melt the chocolate and coconut oil in a microwave safe bowl, stirring every 30 seconds until fully melted
Pour the chocolate over the Peanut Butter Rice Krispie Treats and spread until fully covering the top
Allow the chocolate to cool and dry completely before removing the rice krispie treats from the pan
If you would like them to cool quickly, place the pan in the refrigerator until the chocolate is set
Once the chocolate is dry, remove the Peanut Butter Cup Rice Krispie Treats from the pan and cut them into 2x3 inch bar or your desired size
Serve at room temperature or store in an airtight container until ready to serve 
Enjoy!