Preheat the waffle iron: Follow the manufacturer's instructions to heat your waffle iron. Once hot, lightly coat the plates with nonstick cooking spray to prevent sticking.
Combine the wet ingredients: In a large mixing bowl, whisk together the eggs and sugar until fully blended. Add the ricotta cheese, milk, lemon zest, and vanilla extract, whisking until the mixture is smooth and uniform.
Mix the dry ingredients: In a separate medium bowl, stir together the flour, baking powder, and salt. Gradually add this dry mixture to the wet ingredients, stirring gently until just combined. Pour in the melted butter and whisk briefly to incorporate. Be careful not to overmix, as the batter will be slightly lumpy.
Cook the waffles: Pour about ⅓ cup of batter into the center of your waffle iron. Adjust the amount depending on the size of your waffle maker. Cook for approximately 3 to 4 minutes, or until the waffles are golden brown and crisp on the outside. Remove the waffle and repeat the process with the remaining batter.
Serve and enjoy: Plate the waffles warm, topping them with maple syrup and your choice of fresh fruit or other favorite toppings.