For the stuffing: Mix the ricotta, cream, chives, parsley, lemon zest and anchovy, if using. Season with salt and pepper. Using a piping bag, fill the blossoms with the stuffing. Keep in the refrigerator until ready to fry.
For the marinara sauce: Heat the oil in a saucepan over medium heat. Saute the garlic and onions until the onions are translucent, about 5 minutes. Add the tomatoes and season with salt and pepper. Simmer for about 30 minutes. Using a hand mixer, blend until the sauce is a coarse puree. Stir in the basil, chives and parsley.
For the vodka batter: Mix 1 cup/250 ml flour with the baking powder in a large bowl. Add the club soda and vodka and stir until smooth.
Heat the canola oil in a deep fryer to 350 degrees F (180 degrees C).
Dredge the stuffed zucchini blossoms in the remaining 1/2 cup/125ml flour, then coat with the batter. Fry until golden. Transfer to paper towels to drain. Season with salt and pepper.
Serve the fried blossoms hot with the marinara sauce.
Cook's Note: If you don't have zucchini blossoms, you can stuff mini bell peppers, tomatoes or mushrooms.