Preheat your oven to 350°F (175°C). Grease and flour a 9x5 inch loaf pan or line it with parchment paper.

In a large mixing bowl, combine chocolate cake mix, eggs, vegetable oil, milk, and vanilla extract. Stir until well blended and smooth.

Squeeze the grated zucchini to remove excess moisture, then add it to the batter and fold gently.

Stir in chocolate chips, ground cinnamon, and salt until just combined. Avoid overmixing.

Pour the batter into the greased loaf pan, smoothing the top with a spatula.

Bake for 45–55 minutes, until a toothpick inserted in the center comes out clean.

Let the loaf cool in the pan for about 10 minutes before transferring to a wire rack.

Slice and serve once completely cooled. Store leftovers in an airtight container.