Preheat the oven to 350 and lightly grease a 9x13 pan.
In a saucepan over low heat, melt the butter, then add the sugar and stir to combine. Heat just until the mixture is hot, but don't let it bubble. Watch for it to start looking shiny as you stir it.
In a stand mixer, beat the 4 eggs with the cocoa, salt, baking powder, and vanilla till smooth.
Add the hot butter & sugar mixture to the egg & cocoa mixture, stirring until smooth.
Add the flour and chocolate chips, again stirring until smooth. Remember that if you don't want your chocolate chips to melt, let the mixture cool off for about 20 minutes before adding in the chocolate chips.
Pour the batter into your prepared pan. Bake for about 30 minutes or until the edges of the brownies look set and the center is slightly puffy.
Directions for Frosting:
In a stand mixer, beat together the peanut butter and butter for 2 minutes with the whip attachment. Add in the powdered sugar and beat for an additional 2 minutes, adding milk in if the frosting is not at spreading consistency.
After the brownies have cooled, spread on the icing, as generously as you like. Sprinkle on the Reese's candy. Melt 1 block of semi-sweet chocolate in the microwave for 30 seconds or until melted. Drizzle the chocolate over the top.
The calories shown are based on the brownies being cut into 20 pieces and
all of the frosting used, with 1 serving being 1 frosted brownie. Since different brands of ingredients have different nutritional information, the calories shown are just an estimate.