Preheat oven to 325F
Line 8x8 pan with nonstick foil letting it hang over edges for easy removal later.
In a pot, heat the water to a simmer.
Add cocoa and chocolate.
Remove from heat and stir smooth.
In a large bowl, melt the butter in a microwave.
Add sugar and vanilla.
Add the chocolate mixture.
Add egg/yolk and salt stirring well.
Add flour to combine.
Pour into pan and bake 20 mins. (will not be fully cooked)
Let it cool a few minutes and carefully place the chips and pb cups on top of brownie.