Spray an 8 inch square baking dish with nonstick cooking spray and line with a 12 inch piece of parchment paper. Spray paper with nonstick cooking spray; place a second sheet of 12 inch parchment in the opposite direction so they lay crisscrossed. Spray second sheet with cooking spray; set aside.
Place cream cheese and sour cream in a food processor or blender and blend until smooth. Add in the cocoa powder, cornstarch, sugar, and eggs, blending until smooth, scraping the sides of container at least once.
Pour into baking dish and evenly sprinkle the chocolate chips. Bake on middle rack until just set, about 35-40 minutes.
Place on cooling rack for 20-30 minutes, then in refrigerator for at least 1 hour.
Lift brownies out of pan using the parchment paper as handles, cut into 10 even squares.