In a large microwave-safe bowl, combine the chopped chocolate and butter. Heat in the microwave using short 20 second bursts for 60-90 seconds, stirring between each burst of heat until both are melted and smooth.

Whisk in the sugars until combined. Add eggs, vanilla, and salt. Whisk well until fully incorporated.

Stir in the flour just until combined using a spatula or wooden spoon. Transfer most of the brownie batter to the prepared pan, reserved about 3/4 cup.

In a separate bowl, beat together the softened cream cheese and sugar until smooth. Add the egg and vanilla and beat again until combined.

Dollop spoonfuls of the cream cheese mixture over the brownie batter, then fill in the space between the cream cheese filling with spoonfuls of the reserved brownie batter. Use a skewer or knife to swirl the cream cheese mixure into the brownies.

Sprinkle the chocolate chips over the top of the brownies. Bake for 25-30 minutes until a toothpick inserted into the brownies comes out with only a few crumbs on it. Cool the brownies for at least 2 hours before cutting. We find it much easier to chill completely first before slicing into squares.

Store leftover brownies in the refrigerator and serve chilled or let them sit out on the counter for an hour to come to room temperature before serving.