Preheat oven to 350 degrees.

Prepare 2 baking sheets with parchment paper or spray with baking spray.

Place brownie mix, butter and egg in a mixing bowl.

Mix until no wet spots remain. The dough will be stiff.

Roll dough into 1" balls and place 3" apart on a baking sheet.

Bake 8-10 minutes then cool on a baking sheet.

Completely cool on a cooling rack before filling.

The filling is delicious but very sweet - especially with the white chocolate which is an optional ingredient.

If using the white chocolate;

Combine the white chocolate and cream in a microwave-safe bowl.

Mix well and heat in the microwave 20-30 seconds at-a-time.

Stir well after every 20-30 seconds.

Repeat until chocolate is almost melted then stir.

Set aside and cool about 5 minutes.

In a mixing bowl (use your mixer), combine the cream cheese and butter.

Beat 2 minutes until well combined.

With mixer on low, slowly add the powdered sugar and melted white chocolate (if using).

Beat on high 3-4 minutes.

Add the vanilla and beat on high 1 minute.

With the mixer on low, add the peanut butter cups and beat until well incorporated.

Spread the filling on the flat (or bottom) side of a cookie then top with another cookie.

Smooth out the filling on the sides.

Place the whoopie pies in an airtight container and refrigerate.

The cookies can be eaten at room temperature, but are better cold and easier to eat.

**These can be made with so many fillings and would be delicious made as an ice cream sandwich. The brownie cookies are good even without filling.

ENJOY!!