Preheat the oven to 350 degrees and line a baking sheet with parchment paper.
With a fork, cream together butter, white sugar, and brown sugar in a mixing bowl.
Add peanut butter, egg, and vanilla and mix well.
Next, stir in the flour, salt, and baking soda until mixed completely.
Fold in all of the peanut butter morsels and 1/4 cup Reese’s Pieces (save the rest for the tops of the cookies).
Use a two-tablespoon cookie scoop to create cookie dough balls and place them 2” apart on the prepared baking sheet.
Bake for 10 minutes or until the edges start to brown.
Remove from the oven and top with Reese’s Pieces and chopped Reese’s Miniature Cups.
Let cool for 5 minutes on the baking sheet before moving to a cooling rack to cool completely.