Preheat your oven to 350°F (175°C). Grease a 9x5-inch loaf pan or line it with parchment paper.
In a large bowl, combine the grated zucchini and salt. Let it sit for about 10 minutes to draw out excess moisture, then squeeze out the liquid using a clean kitchen towel or cheesecloth.
In another bowl, whisk together the flour, baking powder, baking soda, garlic powder, black pepper, and cayenne pepper.
In a separate mixing bowl, combine the eggs, vegetable oil, milk, and apple cider vinegar. Whisk until well blended.
Add the squeezed zucchini, shredded cheddar cheese, diced jalapeños, and optional cilantro to the wet ingredients. Stir until combined.
Gradually add the dry ingredients to the wet mixture, stirring gently until just combined. Do not overmix.
Pour the batter into the prepared loaf pan and smooth the top with a spatula.
Bake for 45-50 minutes, or until a toothpick inserted into the center comes out clean. If the top is browning too quickly, cover it loosely with aluminum foil during the last 10-15 minutes of baking.
Allow the bread to cool in the pan for about 10 minutes before transferring it to a wire rack to cool completely.