Mocha Cheesecake Brownie Bars - unsalted butter

Method

• First make the brownie crust. Begin by melting butter in medium saucepan over low heat. Add 2 ounces chopped chocolate to the butter; stir until chocolate melts, and remove from heat. Whisk in 1/3 cup flour, 1/3 cup sugar, 1 large egg, 1/2 teaspoon vanilla extract, and pinch of salt. Spread batter in thin layer on bottom of greased and floured 8 x 8 x 2 inch pan.
• Bake at 350 degrees F (175 degrees C) until tester toothpick inserted into center comes out with only moist crumbs attached, about 10 minutes. Cool.
• Next make the filling. In a small saucepan, stir cream and coffee powder over medium-high heat until coffee powder dissolves. Cool.
• Beat cream cheese and 2/3 cup sugar in large bowl until light and fluffy. Beat in 1 egg and yolk. Add 1/4 cup sour cream, 1 tablespoon flour, 1/2 teaspoon vanilla, and the coffee mixture; beat until smooth. Stir in chocolate chips. Spoon filling evenly over brownie crust.
• Reduce oven temperature to 325 degrees F (165 degrees C). Bake about 35 minutes, or until filling puffs slightly around the edges and center is set. Cool completely on rack. Cover pan with foil, and chill overnight.
• Now make the topping. In a small saucepan, stir 1 cup sour cream and confectioners' sugar over low heat until sugar dissolves; do not boil. Spread topping evenly over filling. Cool slightly. Cover and chill until topping sets, at least 2 hours. Cut dessert into 24 bars. Serve cold.