Prepare cake mix according to package instructions.
Divide the batter into buttered and floured mini cake moulds. Bake for 20 minutes.
Meanwhile make the frosting according to the instructions on the bag. Let the cakes cool.
Unmould the cakes and cut them in half.
Take the cookie dough and spread it on parchment paper and make 24 small discs of the same size as the cakes using a cookie cutter or a knife about 1 cm ½ thick.
Put the cookie dough on two of the three layers of the cakes, cream the sides of the last layer and garnish with the crumbled oreo cookies.
Using a piping bag, spread the frosting on top of the cakes and decorate with the cookies.