Grease an 8-inch baking pan set aside.
Preheat oven to 350 degrees F.
In a large bowl, combine the all-purpose flour, salt, and cocoa powder. Set aside.
Melt butter and chocolate in a heatproof bowl over a pot of simmering water, making sure the water doesn’t touch the bowl. Stir until smooth.
Stir in the sugar and then remove from the heat.
Let the sugar and chocolate mixture cool down a bit.
Add the eggs one at a time and mix until well incorporated.
Stir in the vanilla extract.
Fold in the flour mixture then pour 3/4’s of the batter into the greased baking dish.
In a separate bowl, combine the softened cream cheese, vanilla extract, sugar, sour cream, and egg.
Spread the cream cheese mixture all over the brownies batter.
Using a spoon, dollop the remaining 1/4 of the brownie batter on top of the cream cheese mixture and then use a skewer to swirl the cream cheese mixture and brownie batter.
Bake for 45-50 minutes or until done.