Line and lightly grease a 6-inch square baking tray with parchment paper and preheat your oven to 350°F.
In a saucepan, melt the butter and sugars on low heat. Add the milk and espresso. Turn off the heat, then add the chocolate, letting it melt. Mix until smooth and let it cool.
Sift the dry ingredients into a large bowl.
Pour the wet ingredients into the dry ingredients and mix until combined.
Pour half of the batter into the baking tray.
Dissolve the sugar in the coffee and transfer to a bowl. Dunk each sponge finger in the coffee mixture, then place them on top of the brownie mixture.
Cover with the remaining brownie mixture and bake for 20-25 minutes, or until the top is set.
To make the frosting, beat the cream and powdered sugar together until soft peaks form. Beat in the cream cheese until smooth.
Spread the frosting over the cooled brownies and finish with a dusting of cocoa powder.