1. Preheat oven to 350°F (176°C). Grease a 9×9 baking pan or line it with parchment paper or aluminum foil, which you can use to remove the brownies from the pan when they are done.
2. In a medium sized bowl, combine the flour, cocoa, baking powder and salt. Set aside.
3. In another medium sized bowl, combine the butter, sugar and vanilla extract.
4. Add the eggs and mix until well combined.
5. Add the dry ingredients to the egg mixture and mix until well combined.
6. Pour the batter into the prepared pan and spread evenly.
7. Bake for 18-20 minutes, or until a toothpick comes out with a few moist crumbs.

TO MAKE THE FUDGE AND TOPPING:

8. Combine the white chocolate chips, sweetened condensed milk and peanut butter in a metal or glass bowl. Set the bowl over a pot of simmering water (or use a double boiler).
9. Stir the mixture continuously until everything is melted and smooth. The fudge mixture will start out thinner, but thicken as the white chocolate melts. It’ll even seem a little crumbly when finished. It’s ok.
10. Remove the fudge from the heat and gently stir in the chopped reeses.
11. Pour the fudge mixture on top of the brownies and press into an even layer. The fudge mixture should start to come together as you press it onto the brownie.
12. Set brownies in refrigerator to set, 4-5 hours.
13. For the topping, add the chocolate chips and shortening to a microwave safe bowl. Microwave in 15 second increments until the chocolate and shortening are melted and smooth.
14. Spread chocolate into an even layer over the fudge, then sprinkle with chopped Reeses.
15. Cut brownies into bars. Store brownies in an airtight container in the refrigerator. Brownies are best for 3-4 days, but should be ok for up to 5-6 days.