Chop zucchini in a food processor or by hand with a cheese grater and place in a large mixing bowl.
Sprinkle sugar over the shredded zucchini and stir with a spoon. (This will make the zucchini release some liquid, keep this liquid in the bowl.)
Add the oil and vanilla extract and stir. Then add the dry ingredients and stir slowly until the batter is mixed well and creates a thick batter.
Pour the brownie batter into the oiled pan and bake at 350°F (177°C) for 35 - 40 minutes until the top appears dry and there are some small cracks in the top of the brownies. Allow it to cool completely before adding the optional fudge frosting. (You can also put the brownies in the fridge to help them cool faster.)
For Fudge Frosting
Melt coconut oil and add cocoa powder, powdered sugar, vanilla, and salt.
Mix well with a fork or small whisk to make sure all the clumps are out.
Pour evenly over the brownies. Pick up the pan and rock it back and forth to make an even layer of fudge over the brownies.
The fudge will harden as it cools. Put in the fridge to firm up faster.
Cut into squares.
Notes
To make brownies more fudge-like, reduce baking soda by 1/2 tsp.
To make brownies more cake-like, increase baking soda by 1/2 tsp.
Chop the zucchini very small to hide it better in the brownies.
If topping with fudge frosting, cut into squares when the frosting is firm, but not too hard or it will crack.
This recipe will work with regular wheat flour and most gluten-free flour mixes. (I do not recomend using almond flour in this recipe).
If you have picky eaters, the thin layer of fudge frosting hides any evidence of zucchini. You can also peel the dark green skin off of the zucchini before shredding it to hide the zucchini even more.