Whisk the dry ingredients: In a large bowl, whisk together the flour, sugar, baking powder, and salt.
Combine the wet ingredients: In a separate bowl, whisk together the milk, egg, melted butter, and vanilla extract (if using).
Wet meets dry: Pour the wet ingredients into the dry ingredients and stir until just combined. Don't overmix! A few lumps are perfectly fine.
Blueberry magic: Gently fold in the fresh blueberries. If you prefer a more vibrant blue color, add a few drops of food coloring at this stage.
Heat it up: Preheat your waffle iron according to the manufacturer's instructions. Once hot, lightly grease the cooking surfaces.
Pour and cook! Pour batter onto the preheated waffle iron, filling each section about ¾ full. Close the lid and cook for 5-7 minutes, or until golden brown and cooked through.
Serve and enjoy your blueberry bliss! Carefully remove the waffles from the iron and serve immediately. You can enjoy them plain, or top them with your favorite breakfast goodies like whipped cream, fresh fruit, maple syrup, or even a dusting of powdered sugar for a true "blue willow" experience. The vibrant blue color paired with sweet toppings creates a delightful and whimsical breakfast that's sure to please everyone at the table.