I found this recipe on All Recipes. It was really good! I used my co-op cookie dough instead of making their version. It was still delicious. I'd probably just do that again or use pre-packaged cookies. I used Rachel's rich chocolate frosting that she posted about on this blog.
Cookie Stuffed Cupcakes
1 1/2 c flour
1/4 tsp baking soda
1/4 tsp sea salt
1/2 c butter, softened
1/4 c white sugar
1/2 c brown sugar
2 tsp vanilla extract
1 c miniature semisweet chocolate chips
1 (18.25 oz) bow yellow cake mix
1 1/3 c water
1/3 c canola oil
1. Whisk together the flour, baking soda, and sea salt; set aside. Beat the butter and sugars with a mixer until smooth. Add 1 egg and vanilla and beat until smooth. Mix in the flour mixture until just incorporated. Fold in the chocolate chips. Form the dough into tablespoon-sized balls; place on baking sheet, and freeze until solid, about 2 hours.
2. Preheat oven to 350 degrees. Line 24 muffin cups with paper liners.
3. Beat 3 eggs in a large bowl with a mixer. Add the cake mix, water, and oil. Spoon into the cupcake liners, filling each 2/3 full. Place a frozen cookie dough ball on the top center of each cupcake.
4. Bake in the oven until a toothpick inserted into the cake portion comes clean, about 20 minutes. Cool in the pans for 10 minutes before removing to cool entirely on a wire rack.