Preheat the oven to 350° and line two baking sheets with parchment paper. Set aside.

In a medium sized bowl, combine the melted butter and peanut butter and use a whisk to whisk until smooth.

Add the white and brown sugars to the bowl and mix until well combined.

Next, add in the eggs and the vanilla and give the mixture a good whisk until the wet ingredients are fully incorporated.

Add the flour, baking powder, baking soda, and salt to the peanut butter mixture.

Use a wooden spoon or rubber spatula to stir in the dry ingredients. Stir until the flour is almost fully incorporated into the dough--there should still be visible streaks of flour showing.

Pour the Reese's Pieces and chocolate chips into the bowl and gently fold until all the ingredients are fully incorporated, and no streaks of flour remain. Do not overmix.

Scoop the cookie dough (2 tablespoon size or #30 cookie scoop) onto the baking sheets. Leave a couple of inches between each cookie to account for spreading.

Bake at 350° for 13-15 min, until the edges are set, but the centers still look a little gooey.

Remove the cookies from the oven and let them sit on the sheet pan for 10 minutes before transferring them to a cooling rack. Serve and enjoy!