Brownie Cupcakes with Peanut Butter Frosting

These are so delicious! They look like they took a long time to make, but they are actually quite simple!
Brownie Cupcakes with Peanut Butter Frosting
What you need:
1 box of brownie mix (my favorite are the Ghiradelli Double Chocolate Brownie Mix...if I am going to go all out, I might as well go out with style!)
All the ingredients for the mix (I think  it is 1/3 cup of vegetable oil, one egg and some water...follow the back of the box)
Cupcake liners (if you want...not needed)
1 vanilla or cream cheese frosting tub (my favorite...Duncan Hines)
3-5 Tablespoons of Peanut Butter (my favorite...Jif)
Reese's Mini Peanut Butter Cups (about 18, unwrapped)

Preheat oven to 325*. Mix brownie mix with ingredients in a bowl. Prepare a cupcake pan with liners, if desired. Spoon brownie mix into cupcake tin, about 2/3 full. Bake in the oven for about 18 minutes or until brownies are not gooey in the middle (a toothpick test should come out with gooey crumbs...do not overbake!). Pull out of the oven and let the brownies cool for 30 minutes. While the brownies are cooling, pour frosting tub into a bowl. Add at least 3 tablespoons of peanut butter to the frosting tub, if you want more of a peanut butter taste, simply add more peanut butter! When brownies are cooled, frost each brownie and place one Reese's cup on each cupcake.