The idea of stuffing seems strange, particularly with cookies. Sure, we might stuff birds (this could have a few definitions, some dubious!) and some people create rather outrageous desserts-within-desserts, such as the ridiculous, 1800-calorie-per-slice pumpple cake. Nevertheless, there is something compelling about the idea of biting into something you think is one thing and finding something else (appealing!) inside. Most people like chocolate chip cookies, most people like brownies. What's not to like about combining the two? (Unless you're me and don't like chocolate, of course. I have not tasted these, so I don't know if they are worth the effort — I will poll my jury of peers at work tomorrow!)
First you will need to make brownies to stuff into the cookies and give them time to cool before cutting into small pieces to use as stuffing. I misplaced my recipe for this but will post it when I find it again. You can also feel free to use a pre-packaged brownie mix (I might have done this if one were available, as much as I hate pre-packaged anything. It just would have saved a step).
1 cup cubed, cold butter
1 1/2 cups brown sugar
2 large eggs, cold
2 teaspoons vanilla extract
3 1/2 cups flour
1 teaspoon baking powder
1/2 teaspoon baking soda
1/2 teaspoon salt
2 cups semi-sweet chocolate chips
Preheat oven to 350F. Line baking sheets with parchment paper.
Beat butter and sugar until barely combined, about 1 minute on lowest speed. Unlike normal dough, you should not strive to make this butter-sugar combination fluffy! Add the egg and vanilla and beat until combined.
Mix together the dry ingredients and add them to the butter and sugar mixture. If needed (should dough be too sticky), add another tablespoon of flour. Add the chocolate chips and mix until combined. Although not required, you can chill the dough now to make the stuffing process easier (I did). After chilling for about an hour, use an ice cream scoop or small measuring cup to scoop rounds of cookie dough. Hollow out the middle and add a brownie to the hole. Cover with more dough and place on prepared baking sheets. (I chilled the baking sheets again for a few minutes in the fridge – I thought it might help the cookies retain their shape and not spread all over the pan; this seemed effective.)
Bake 10-12 minutes (until the edges are lightly browned.)