Preheat oven to 350 degrees and prepare a baking sheet with parchment paper.
In a mixer fitted with a paddle attachment, mix butter, sugar, brown sugar, and peanut butter until nice and creamy.
Add eggs and vanilla.
Slowly add in flour, salt, and baking soda.
Fold in Reese's Pieces.
Scoop round balls onto cookie sheet and bake for 10-12 minutes.
Move cookies to a wire rack to cool completely.