2¼cups (more or less)powdered sugar (sifted after measuring)
Preheat oven to 350° F. Line a 9x9-inch pan with foil and spray with nonstick cooking spray.
PREPARE THE BROWNIES:
In a medium bowl, sift the flour, salt and baking powder; set aside.
Set a heatproof bowl over a pan of simmering water (pan shouldn't be touching the water). Place the chocolate chips and butter in the bowl and stir until melted and smooth. Remove from heat and let cool a bit.
In a large bowl with an electric mixer, combine the sugar, 1/2 cup Kahlua and eggs. Pour in the buttery chocolate mixture and beat until mixed well. Mix in the dry ingredients and beat just until combined.
Pour the brownie batter into the prepared pan. Bake for 40 to 45 minutes, or until the top cracks slightly and a toothpick inserted into the center comes out mostly clean (it might be slightly gooey on the bottom of the toothpick- that's okay!) Remove the brownies from the oven and immediately brush warm brownies with 2 tablespoons of Kahlua. Let the brownies cool completely. I like to refrigerate them after they have cooled down a bit.
PREPARE THE ICING:
Place the butter in a saucepan and heat until lightly browned. Remove from heat and add Kahlua and whipping cream. Whisk in the powdered sugar until you have the consistency that you desire (you should be looking for a thick, smooth icing that is still pourable). Pour on top of the cooled brownies and spread to the edges to cover completely. Refrigerate until set. Chilled brownies are easiest to cut... use a large, sharp knife, wipe clean after each cut, and you'll get nice, clean cuts.
*Store brownies in covered container. They're best if eaten within a couple of days.