Preheat the oven to 350°F. Line baking sheets with silicone baking mats or parchment paper.

Combine flour, baking soda, and salt in a medium bowl and whisk well.

In a large bowl, cream melted butter, peanut butter, brown sugar, and granulated sugar until smooth.

Add the egg and vanilla to the mixture and beat until combined.

Gradually add dry ingredients to the wet mixture and mix just until combined. Stir in Reese’s Pieces candies.

Using a cookie scoop, form dough balls and place on prepared baking sheet at least 2 inches apart.

Gently flatten each dough ball and bake for 10 minutes or until edges are golden brown.

Remove cookies from oven and press additional Reese’s Pieces into the top while hot.

Allow cookies to cool on the baking sheet for at least 10 minutes before transferring to a wire rack to cool completely.