Preheat the oven to 180°C (360°F) and start by coarsely grating the zucchini.
In a bowl, combine all the dry ingredients and whisk until smooth and free of clumps.
In a separate bowl, mix the wet ingredients until the soy milk begins to foam lightly.
Now combine the wet mixture, dry mixture, and grated zucchini. Mix until you have a smooth, soft dough. If you have mixed it enough there will have been enough water released from the zucchini into the batter.
Pour the batter into a greased, flat baking dish, spreading it evenly so you have it easy when cutting the brownies into squares later. Bake in the preheated oven for 30–35 minutes.
Let the brownies cool completely before spreading a layer of apricot jam evenly over the top. Next, pour the melted chocolate mixture over the jam, spreading it carefully to cover the entire surface. For an optional finishing touch, sprinkle some chopped hazelnuts on top.
Once the chocolate has cooled and firmed up, cut the brownies into squares and enjoy!