I recently arranged lunch orders for my school. Each one came with a cookie dessert and we were all dealt a different cookie hand, but some of the gals got cookies with candy pieces inside. They were the fan favorite.
I made these a million years ago, and there are a ton of ways to make them from scratch, but...I like the cheater way.
I bought a thing of premade cookie dough and a row of fun size snickers. I cut them into 1/4ths (about one inch pieces) and then use just enough dough to cover them on top and bottom.
I set them on trays and backed them as the package instructed.
The chocolate melts and flattens and once it cools you've added a nutty/caramel center of goodness to an already delicious cookie. It's always fun to find a prize inside!