In the bowl of a stand mixer fitted with the paddle attachment, or in a large mixing bowl using an electric mixer, beat the PHILADELPHIA Cream Cheese and sour cream together until smooth.
Then mix in the sugar and vanilla until fully combined, stopping to scrape down the sides of the bowl as needed.
Mix in the eggs, one at a time, on low speed until each one is just combined.
Pour the cheesecake filling on top of the brownie layer and spread it into one even layer.
Return to the oven and bake 350°F (177°C) for 25-30 minutes or until the edges of the cheesecake are set, but still slightly jiggly in the center.
Remove from the oven and cool completely on a wire rack, then cover tightly and refrigerate for 3-4 hours or until the bars are completely chilled.
Cut into squares, drizzle with the melted chocolate, and place back in the refrigerator for 10-15 minutes or until the chocolate is firm, then serve and enjoy.