Mix brownie mix with eggs and oil.

Roll brownie mix into 24-26 similar sized balls.

Place cookie balls on baking sheets covered in parchment paper.

Bake at 350° for about 13 minutes. Ovens vary do not over bake-you do NOT want the brownie cookies to be hard.

While the cookies bake, make the creme filling: Combine Cool Whip with the marshmallow creme, using an electric mixer (peaks should form). Combine well and refrigerate.

When cookies have baked and cooled, spread or pipe marshmallow creme filling on 12 or cookies. Place the other 12 or 13 cookies on top-making cookie sandwiches.

Serve or refrigerate. If you refrigerate, remove the cookies from the refrigerator 10-15 minutes before you want to serve them.