4ounces chocolate (bittersweet or semi-sweet), chopped
3Tablespoons heavy cream
Preheat oven to 350°F and line a 9x9" pan with parchment paper. Lightly grease with non-stick cooking spray.
Mix brownie mix with ingredients listed on package. Then pour about 2/3 brownie mixture into pan.
Mix butter, peanut butter and powdered sugar together until smooth. If it gets too thick, add a Tablespoon of milk as needed. Using a spoon, drop spoonfuls of peanut butter filling on top of brownie mixture.
Then add remaining 1/3 brownie mixture on top of peanut butter and smooth out with spatula if needed.
Bake for 30 minutes, or until a toothpick comes out clean. Remove from oven and allow brownies to cool completely.
Heat the heavy cream in the microwave for about 30 seconds, or until very hot. Then pour cream over the chopped chocolate and cover with saran wrap. Allow to sit for a few minutes to melt.
Stir ganache until smooth, then pour over cooled brownies. Use a spatula if needed to smooth out the ganache. Refrigerate for 1 hour before serving.
Line your pan with parchment for easy removal.
Can add chopped Reese's to the peanut butter filling before baking or on top of chocolate ganache.
Feel free to mix in some chocolate chips to your brownie batter.
You could omit the chocolate ganache if preferred.
For a thinner brownie, add batter to a 9x13" baking dish. Baking time will likely be shorter, about 20-25 minutes.