Preheat the oven to 350 degrees F.

In a medium bowl, whisk together the flour, baking soda, and salt. Set aside.

In a large bowl, with an electric hand mixer, beat together the melted butter, peanut butter, brown sugar, and granulated sugar until combined.

Then beat in the egg and vanilla, until well incorporated.

Add the dry ingredients (to the wet ingredients. Using a wooden spoon, mix this until just combined.

Fold in the Reese’s pieces.

Line your baking sheets with parchment paper or silicone mats. Using a cookie scoop, grab some of your cookie dough and shape the dough into 16 balls and smooth out using your hands.

Place the cookie dough balls on the prepared baking sheets, leaving at least 2 inches of space between each one. Flatten each one just slightly with the bottom of a heavy glass.

Bake the cookies for 10 minutes until the edges to be just starting to turn golden, and the middle should still be soft.

Once they are done baking, remove from the oven and press more Reese's Pieces to the top of each cookie.

Let cookies cool on the baking sheet for 10 minutes. Then move them to a wire rack to cool completely.