Yes, you can definitely stuff these delicious mini brownie bites. Press these extra ingredients into the brownie batter once it has been poured into the tin before it has been baked. Any type of nuts, chocolate chips or candy are delicious stuffed into these brownie bites. You will want the add ins to be cut into little pieces so that you can get a small amount in each bite. These brownies are a hit no matter how you chose to serve them.