Grate the zucchinis and place them in a clean kitchen towel or several strong paper towels. Squeeze out as much water as possible, doing this over a colander to catch any escaping liquid.

Preheat your waffle iron. In a large bowl, mix all the ingredients until well combined. If the zucchini is too watery, add an extra 1/4 cup of flour. Let the batter sit for 10 minutes to allow it to thicken.

Generously spray the preheated waffle iron with nonstick cooking spray. Pour about 1/4 cup of batter onto the iron for each waffle. Cook according to your waffle iron's instructions, usually for 2-4 minutes per batch, until the waffles are golden brown. My waffle iron makes 4 waffles per batch. Repeat until all the batter is used, spraying the iron between batches.