Peanut Butter Swirl Mini Brownies

My son and I wanted to make something special for my daughter's after school treat today. We finally decided to make peanut butter swirl brownies. I found this recipe on Ezra Pound Cake that looked delicious but I adapted it to make little mini brownies using mini muffin tins. My son had a great time stirring up all the ingredients and an even better time gobbling up the tasty brownie bites. My