Preheat oven to 325°F.
Spray and line an 8 x 8″ pan with parchment paper.
Combine flour, baking powder, baking soda, cocoa and spices in a bowl and set aside.
In a separate bowl, beat eggs, oil and sugar until creamy.
Stir in oats and vanilla.
Add in dry ingredients, zucchini and chocolate; mix until just combined.
Pour into the prepared pan and bake for 30 minutes or until cake tests done.
Remove from oven and cool completely.
Whisk icing ingredients together until smooth and spread over the cake once it’s cooled.