Preheat the oven to 200 degrees F. In a large bowl, combine the zucchini, onions, basil, zest , garlic, salt, and pepper. In a small bowl, combine the flour and baking powder. Add the eggs and flour mixture to the vegetables and stir just until combined. Heat a large, nonstick skillet over medium-high heat for 3 minutes. When hot, add enough oil to coat the bottom of the pan. Add the batter by tablespoons into the skillet (making sure to spoon both batter and vegetables), leaving 1-inch between the cakes. Immediately drop a round of cheese into the center of each pancake . Top with another tablespoon of batter to enclose the cheese. Cook until golden brown on the bottom side, about 1 1/2 minutes. Flip with a spatula and cook on the 2nd side until golden brown, about 1 minute. Remove from the pan and place on a baking sheet. Keep warm in the oven while preparing the remaining pancakes. Arrange the pancakes on a platter, drizzle with the tomato sauce, and serve immediately. Heat the oil in a large saucepan over high heat. Add the onions, carrots, salt, and black pepper and cook, stirring, until the onions are soft, about 2 minutes. Add the garlic and cook, stirring, for 30 seconds. Add tomatoes, basil, oregano , and cayenne, and cook for 1 minute. Add the stock and bring to a boil . Reduce the heat and simmer , stirring occasionally, until thickened and fragrant, about 15 minutes. Remove from the heat and puree in a food processor or blender . Serve immediately over the Stuffed Zucchini Pancakes, or store, refrigerated, in an airtight container for up to 2 days. Reheat in a saucepan over low heat. Yield: about 1 1/2 cups