Preheat the oven to 325°F and line an 8 x 8-inch baking pan with parchment. Butter the parchment and sides of the pan.
Place the chocolate and butter in a microwave-safe bowl and heat in the microwave in 20-second increments, stirring each time, until the chocolate and butter have melted. Allow to cool slightly.
Whisk the sugar, eggs, vanilla, zest, cardamom, and salt into the chocolate-butter mixture. Mix well until smooth. Place the chocolate chips in a small mesh strainer over the bowl and then pour the flour over the chips. Sift the flour through the strainer, which will simultaneously coat the chocolate chips in flour. Stir the flour into the batter until just combined and fold in the flour-coated chips.
Pour the batter into the prepared pan and bake for 25-35 minutes or until the brownies are just set. I like my brownies fudgy, so I take them out around 30 minutes.
Allow the brownies to cool completely and then top with the glaze. The glaze will need 15 minutes or so to set up (I put mine in the fridge to help it along). Once the glaze is hardened, slice and serve!
For the Glaze:
Whisk together the juice, zest, and roughly 1 cup of the powdered sugar until smooth. If the glaze is too runny, keep adding powdered sugar as needed to thicken it up. Pour over the cooled brownies.
As you can see from the pictures, my glaze was still fairly runny. I took the pictures before allowing the glaze to set, which is what I wanted for a gooey effect. The glaze will definitely harden up more the longer it sits.