1. Preheat oven to 350 degrees F. Spray 20 cups of 2 (12 cup) muffin pans with cooking spray, or line with paper liners.
2. Place butter in a medium microwave-safe bowl and cut each stick into 6 to 8 pieces. Add chopped chocolate and heat on high for 1 minute. Stir until fully melted; if needed, return to microwave and heat for 10 to 20 additional seconds. Stir until smooth, then add sugar and continue to stir for another minute until blended. Let cool for about 2 minutes.
3. While mixture is cooling, whisk together flour, cocoa, baking powder, and salt in a large bowl.
4. Reheat chocolate mixture on high in the microwave until it becomes shiny when you stir it, about 30 seconds -,- this will let the sugar melt and create a shiny top to the brownies. Pour mixture into bowl with dry ingredients. Add vanilla. Slowly add eggs and stir until smooth with a wooden spoon. Place a tablespoon of batter into each of the prepared muffin cups.
5. Spread about 1/2 tsp. peanut butter on one side of each Oreo. Place 1 Oreo, peanut butter side down, on top of the batter in each muffin cup.
6. Divide remaining batter among the 20 muffin cups, making sure batter covers each Oreo completely.
7. Bake until a toothpick inserted along the side of one of the cupcakes comes out clean, about 17 to 22 minutes.
8. Cool brownie cups in the pan for 5 to 10 minutes to ensure that they will not fall apart when you take them out. Gently remove brownies from pan and place on a wire rack to cool. Serve warm or at room temperature, garnished with a dab of peanut butter and a mini Oreo if desired.
Source: Hannaford fresh Magazine, May - June 2015