Heat oven to 350. Lightly grease a 33 cm x 23 cm baking pan.

For Bar Layer: melt butter and chocolate in a small saucepan over low heat (or in microwave in a bowl on high, stirring every 30 seconds until melted.) Set aside to cool.

Mix flower, baking powder and salt. In a large bowl beat brown sugar, eggs, powdered coffee and vanilla until blended. Stir in cooled chocolate mixture. Add flour mixture. Spread batter in an even layer in the prepared pan.

For Cheesecake Layer: beat cream cheese, sugar and flour in a large bowl with an electric mixer on medium speed until pale and fluffy. Add eggs, one at a time, beating well after each. Add eggs, one at a time, beating well after each. Beat in liqueur (or coffee), vanilla and cinnamon. Carefully pour over brownie layer and spread into an even layer. Bake 20 minutes, until top is almost set.

Meanwhile, make the sour cream layer by mixing the sourcream and sugar. After bars have baked for 20 minutes, remove pan from oven and carefully spread sour cream mixture over top. Bake for 10 minutes longer. Cool completely on a wire rack before cutting into bars.