1. Line a cookie sheet with parchment paper and set aside. Preheat oven to 350 degrees F.
2. In a large bowl, whisk together butter, both sugars and eggs until creamy.
3. Add peanut butter, oats, flour and baking powder. Mix together until all ingredients are well-combined.
4. Add Reese’s Pieces and carefully fold into batter.
5. Use an ice cream scoop to drop cookie batter onto the lined cookie sheet, about 2 inches apart from each other.
6. Bake for 10-13 minutes and allow to cool before serving. Enjoy!