Preheat the oven to 350 degrees F (177 degrees C).
For the brownies: In a heatproof bowl set over (but not in) a saucepan of gently simmering water, combine the butter, the brown sugar, the cocoa powder, the instant coffee and the salt. Stir continuously until the butter is melted and the mixture is smooth and hot to the touch, about 8 minutes.
Remove from the heat and stir with a silicone spatula until cool, about 2 minutes. Stir in the eggs, one at a time, and then the vanilla until the mixture gets very shiny and smooth, about 2 minutes. Your arm may get tired, but 10 more stirs and you are done! Now rest for a second, and then fold in the flour. The batter will be very thick.
Spray an 8-by-8-inch (20-by-20-centimeter) baking dish with nonstick cooking spray and line with two 14-by-4-inch strips of parchment paper; the parchment will make a cross in the bottom of the dish and raise out of the sides. (This creates tabs that will help you remove the brownies from the pan later.) Pour in the batter and bake until the center has just set, 20 to 25 minutes. Cool completely.
Meanwhile, for the icing: To a stand mixer fitted with the whisk attachment, add the butter and mix on medium until smooth. Turn the mixer off and add half of the powdered sugar and mix on low to combine. (I sometimes wrap a kitchen towel around the top to capture any flyaway powdered sugar.) When the powdered sugar is incorporated, turn the mixer off and repeat with the remaining sugar. Add the cardamom to the bourbon and stir to distribute the spice. With the mixer going on low, drizzle in the bourbon and continue to mix until smooth.
Slather the icing onto the brownie and spread evenly across the entire top. Refrigerate until the icing is cold.
When the icing is chilled, make the ganache: Place the chocolate chips in a heat resistant glass bowl. Heat the cream in a small saucepan over medium heat until it just begins to simmer. Pour the hot cream over the chocolate and let stand for 2 to 3 minutes. Whisk the chocolate to make sure all the pieces melt. Cool slightly. (You don't want it to be too hot, which would melt the icing.)
Pour the melted chocolate over the icing and spread evenly to cover the entire top. Place back into the refrigerator and allow the chocolate to set up. This will take about 30 minutes.
When you are ready to serve: Run a paring knife along the sides to release any chocolate or brownies from the pan. Use the tabs to lift the brownies out of the pan. Using a sharp chef's knife, divide into 16 even pieces. Enjoy!