Begin by grating the zucchini into a medium bowl. Sprinkle 1 teaspoon of salt over the grated zucchini and mix it in. Allow it to drain in a strainer for 30 to 60 minutes.

In a large mixing bowl, combine the prepared vegetables, including the drained zucchini, chopped broccoli, grated carrots, and sweet corn kernels. Gently fold until well incorporated.

In a separate bowl, whisk together all-purpose flour, baking powder, salt, pepper, granulated garlic, breadcrumbs, and optional Parmesan cheese. Sift to avoid lumps.

Sprinkle the dry ingredients over the vegetable mixture and gently toss until all veggies are coated. Create a well and pour in the whisked eggs. Mix thoroughly.

Heat oil in a skillet over medium-high heat. Drop spoonfuls of the mixture into the skillet, flattening them to form patties. Cook for 5 to 6 minutes on each side.

Remove the patties and place on a wire rack or paper towel-lined plate to drain excess oil. Continue cooking remaining mixture.

Store any leftover cakes in an airtight container in the refrigerator for up to 5 days or freeze for up to 3 months with parchment paper between layers.