Preheat the oven to 350° and have ready an 8 inch square baking pan lined with a sheet of parchment paper or nonstick aluminum foil.

In a medium-sized saucepan combine butter and unsweetened chocolate over medium heat and stir until melted. Remove from the heat and set aside until just warm to the touch, about ten minutes.

Add sugar to the chocolate mixture and using a handheld mixer, beat on medium speed until combined. Add the eggs one at a time, mixing well after each addition. Add the vanilla and mix once more. Set aside until ready to use.

In a mixing bowl, whisk together flour, baking powder and sea salt. Add the flour mixture to the saucepan and mix on low, until ingredients are fully incorporated. Transfer to the brownie pan and bake thirty minutes, or until a toothpick inserted in the center still comes out moist, but not coated with batter. Set aside to cool on a wire rack fifteen minutes.

Remove the brownies from the pan and cut into sixteen squares. Set atop a sheet of wax paper, spaced one inch apart. Add three ounces of the white chocolate to a small microwave safe bowl and microwave in thirty second increments, stirring well in between each session, until the chocolate has melted. Add in the remaining ounce of chocolate and stir until melted.