Cheesecake Filling: 

1. Place cream cheese in a microwave safe bowl, then heat for 30 seconds until easily spreadable. Add the mascarpone, sugar, and flour, then whisk to combine. Set aside.

Brownie Batter: 

1. Preheat oven to 325 F and place rack in the middle position. Line an 8" x 8" baking pan with aluminum foil, then spray well with nonstick baking spray. 
2. Whisk together flour, espresso powder, baking powder and salt. Set aside.
3. Combine chocolate and caramel chips with butter in a bowl, then microwave in 30 second increments until completely melted, stirring after each interval. 
4. In a large mixing bowl, whisk together sugar, eggs, and vanilla. Add the chocolate-caramel mixture, then whisk until smooth. Add flour mixture and fold until just combined. 
5. Pour all except 1/2 cup of the brownie batter into the prepared pan. Top with cream cheese filling, and spread evenly along the top. 
6. Dollop the remaining brownie batter on top, then use the edge of a knife to swirl batter into cream cheese.
7. Bake for 40 minutes, or until toothpick or cake tester inserted into the brownies comes out clean. Let cool in pan for 1 hour. Cut into 9 equal squares.