Preheat oven to 350°F. Cover a cookie sheet with parchment paper & set aside.
In smaller bowl, mix flour, baking soda and salt. Set aside.
In a mixing bowl, add butter and shortening and mix well until pale and creamy looking. Add in sugars and mix until combined. Add the eggs and vanilla; mix again.
Pour the flour mixture into the butter mixture and mix until dry ingredients are incorporated.
Stir in the mini chocolate chips, peanut butter chips, 1/2 cup Mini Peanut Butter cups and 1/3 cup Mini Reese's Pieces.
Combine both sizes of the leftover Reese's Pieces into a shallow bowl.
Scoop the dough out using a medium sized cookie scoop and then press the ball of dough into the bowl of Reese's. Use your hands to gently turn the cookie dough right side up, pressing the Reese's Pieces into the dough so that they don't fall off. The top part of the cookie dough ball should be covered with Reese's.
Take 1 of the remaining Mini Peanut Butter Cups and press it into the top of the dough ball, amongst the Reese's Pieces. Now the cookie dough should be pretty loaded with Reese's!
Place the dough balls on the prepared baking sheet about 1.5”-2” apart.
Bake for 11-12 minutes until the cookies just barely begin to turn light brown on the edges.
Let them cool on the baking sheet for 10 minutes before transferring to a wire cooling rack. Enjoy!