Step 1

Preheat your oven to 180C/350F, and line a 20cm/8inch cake pan with parchment paper.

Step 2

In a large bowl, whisk together flour, cornstarch, cocoa, baking powder, baking soda, and salt.

Step 3

In a separate bowl, combine soy milk, apple cider vinegar, peanut butter, syrup, vegetable oil, apple puree, flax egg, and shredded zucchini, whisking until well blended.

Step 4

Mix the liquid ingredients into the dry ingredients until a smooth batter forms.

Step 5

Pour the batter into the prepared cake pan and bake for 50 minutes. Test for doneness using a toothpick, and allow the cake to cool completely.

Step 6

While the cake cools, make a quick frosting by blending the listed ingredients until smooth. Transfer the frosting to a piping bag and refrigerate for an hour before assembling.

Step 7

Cut the cake in half and spread ⅓ of the frosting on the bottom half. Add more frosting on top and use a spatula to create a smooth surface. Optionally, decorate with chocolate chips.