Preheat oven to 350 degrees.
Line 9x13 in baking pan with parchment paper.
Using a double boiler, add 1/2 cup of water in the bottom of the double boiler.
Place the double boiler over medium heat until it boils.
Add the chocolate chips, unsalted butter, and unsweetened chocolate baking squares in the top of the double boiler.
Cook on simmer while stirring occasionally for 5-6 minutes or until it is melted.
Remove from heat allowing the chocolate to cool for 10 minutes.
In a large bowl add the eggs, sugar, and vanilla whisking to combine.
Slowly add the warm chocolate mixture to the egg mixture whisking to combine.
Set aside to cool for 10 minutes.
In a third bowl sift the flour, baking powder and one of the 1/2 tsp of salt.
Whisk as you add this to the chocolate mixture.
Set aside 2/3 cup of the batter.
Pour the batter into the prepared baking pan.
Set brownies aside.
In another bowl whisk the pumpkin, eggs, heavy cream, brown sugar, pumpkin pie spice, and the last 1/2 tsp of salt together.
Pour this over the brownie batter.
Scoop the reserved brownie batter on top of the pumpkin topped brownies.
Using a knife swirl the last brownie batter gently to make a
design.
Bake at 350 degrees for 45 to 50 minutes. (Insert a toothpick in the center and remove. If the toothpick comes out with a few crumbs then it is done.)
Cool completely on a wire rack. (About two hours)
Remove brownies from the pan and allow to cool overnight before cutting.