• Preheat the oven to 350°F (177C°). Line an 8 inch square baking pan with parchment paper and spray with cooking spray. Set aside.

Make the brownie layer:

• In a heatproof bowl set over a saucepan of simmering water, melt the butter and chocolate, stirring continuously. Remove from heat and stir in sugar and vanilla extract.
• Add the eggs one at a time, beating well after each addition.
• In a medium bowl, whisk together the flour, cocoa powder, espresso powder and salt. Make sure there are no lumps.
• Add the flour mixture to the chocolate mixture in two additions, beating on low-speed until just combined. Do not overmix. Batter should be smooth and glossy. Remove 1/4 cup of brownie batter and set aside. Spread the remaining brownie batter into the prepared pan.

Make the cheesecake layer:

• In a medium bowl, beat the cream cheese until smooth. Add the sugar, egg and vanilla extract. Beat on medium speed for 1 minute until smooth and creamy.
• Spread cheesecake mixture over the brownie batter. Add one tablespoon of very hot water to the 1/4 cup of reserved brownie batter and mix well.
• Dollop the brownie batter over the cheesecake layer. Use a skewer or knife to swirl the two layers together.
• Bake for 28-30 minutes or until a toothpick inserted in the center comes out clean. Note: the cheesecake will be jiggly, but will firm up as it cools.
• Transfer pan to a wire rack to cool completely. Place in the refrigerator for 2 hours or overnight before using the parchment paper overhang to lift the brownies out of the pan. The cheesecake layer must be cold before cutting. Cut into 9 large brownies or 16 small brownies, wiping the knife clean between each cut. Tip: microwave individual brownies for 10 seconds each just before serving.