Preheat the oven to 350 degrees F. Prepare a sheet pan by lining it with parchment paper or a Silpat liner.
In a large bowl (stand mixer recommended, a hand mixer will also work), cream together the cream cheese and butter. Both should be slightly soft, but not melted. Add in the egg and vanilla extract. Mix well.
Beat in the brownie mix and pudding mix until just combined.
Gently fold in the chocolate chips. The dough is thick and sticky! If it's too hard to work with, cover and refrigerate for 10 minutes and then continue. (See Note 1.)
Roll large balls of dough (a packed 2 tablespoons in size; 40g each) and then slightly press down on the cookie dough balls to form a disc-like shape.
Bake for 8-12 minutes and then remove from the oven. (Baking time may vary based on the size of your cookies and actual oven temperature.) It's best to slightly underbake these cookies to keep them soft, fudgy, and chewy! If desired, top the cookies with a few more chocolate chips (just to make them look pretty!).
Allow cookies to continue to stand on the cookie sheet for an additional 3-4 minutes before removing them to a cooling rack. If desired, add a sprinkle of salt to the cookies while warm.