Preheat the oven to 350°F and spray a 9x13 baking pan with non-stick spray.
Sift all purpose flour and cocoa powder into a mixing bowl and add white sugar, salt and instant coffee and mix together.
Add shredded zucchini, oil, egg and vanilla and mix into a thick batter. If you have any trouble getting it mixed in, then leave the bowl for a minute, and then come back to it. The zucchini will release more moisture into the batter and when you come back to mix it will come together easily.
Transfer the batter to your prepared 9x13 baking pan and smooth down with the back of a spoon so that it reaches all the corners.
Bake for 25 minutes until a toothpick inserted into the center comes out mostly clean. Moist crumbs are fine, wet batter is not.
While the brownies are cooling, prepare your chocolate fudge topping.
Melt the butter in a saucepan and then add the sugar and milk.
Stir continuously until it reaches a full boil, then remove from the heat and add chocolate chips and stir vigorously until they have melted and you have a smooth chocolate sauce.
It will start setting pretty fast, so immediately pour it over the top of the still warm brownies and let it set completely.
Cut into squares and enjoy.