peanut butter brownie whoopie pies

Brownie Cookie Ingredients:

box brownie mix (I used Betty Crocker Fudge Chewy Brownie)

unsalted butter (1 stick) - melted

egg - slightly beaten

Filling Ingredients:

white chocolate melting wafers or baking chips( Ghirardelli) (opt.)

heavy cream (opt.)

unsalted butter - softened to room temperature.

pwdr. sugar

pkgs cream cheese (16 oz) - softened to room temperature.

vanilla extract or 2 t vanilla bean paste

Reese's Peanut Butter Cups - regular size - chopped into small pieces