Preheat the oven to 350°F (175°C). Grease a 9x13 inch baking pan.

In a medium bowl, whisk together the flour, cocoa powder, baking soda, baking powder, salt, and cinnamon.

In a large bowl, beat the butter, oil, and sugar until well combined. Add the eggs one at a time, beating well after each addition. Stir in the vanilla extract.

Gradually add the dry ingredients to the wet ingredients, mixing until just combined.

Fold in the grated zucchini, diced apple, and chocolate chips.

Pour the batter into the prepared pan and spread evenly.

Bake for 40-45 minutes, or until a toothpick inserted into the center comes out clean.

Allow the cake to cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.

Once cooled, cut into squares and serve. This cake is perfect for picnics or outdoor gatherings!