Preheat oven to 325. Place parchment paper in bottom of 8x8 or 9x9 inch pan. Melt butter in microwave safe bowl, let cool.
Combine sugar,cocoa and salt. Using wooden spoon stir in melted butter, combine. Stir in vanilla and eggs(one at a time) Gently stir in flour until just combined, DO NOT OVER MIX. can make batter stiff and dry.
Sprinkle the remaining cocoa in bottom of baking dish, add half the batter, place p.b cups on top, pour in remaining batter.
Bake 25-30 min, it really depends on your oven, i started mine at 325 then turned up to 350 for the last 5 min. Check with toothpick it should come out with some soft batter on it.
Place dish on cooling rack,let settle. lift with edges of parch paper to counter, let cool until set, slice then ENJOY!