Preheat oven to 350F. Using pan spray or butter grease the bottom and sides of an 8x8 Baking Dish.

Melt both butters in a Saucepan or Saucier over medium heat.

Add chocolates to Saucepan and whisk until fully incorporated and smooth. Remove from heat and set aside.

Combine flour and baking powder in a bowl and whisk together. Set aside.

In a different bowl whisk together eggs, sugar, vanilla, and salt until batter is light and fluffy.

Add chocolate mixture to the bowl, then add flour mixture and mix until combined.

Pour into a baking dish. Bake  for 20-25 minutes. Top the brownies off with flakey salt if desired.

Allow to cool before cutting. Cut into 12 pieces at 5-10mg each.