Preheat the waffle iron. Set it to medium or follow your machine’s standard setting. A properly heated iron helps prevent sticking and creates crisp edges.

Mix the dry ingredients. In a large bowl, whisk together flour, cornstarch, sugar, baking powder, baking soda, and salt until evenly combined.

Combine the wet ingredients (minus egg whites). In a separate bowl, whisk the milk (or buttermilk), egg yolks, melted butter, and vanilla until smooth.

Make the batter. Pour the wet mixture into the dry ingredients and gently whisk until just combined. A few small lumps are fine. Avoid overmixing, which can make waffles tough.

Whip the egg whites. In a clean bowl, beat the egg whites to soft peaks using a handheld mixer or whisk. They should hold their shape but still look glossy.

Fold in the egg whites. Gently fold the whipped whites into the batter with a spatula in two batches. This adds air and keeps the waffles light.

Grease the iron. Lightly oil or spray the waffle plates to prevent sticking. Even nonstick surfaces benefit from a quick coat.

Cook the waffles. Ladle batter onto the center of the hot iron, just enough to cover the grid once pressed. Close the lid and cook until golden and crisp, usually 3–5 minutes, depending on your iron.

Keep them crisp. Transfer finished waffles to a wire rack set over a baking sheet in a 200°F (95°C) oven while you cook the rest. This prevents sogginess.

Serve warm. Top with butter and maple syrup, or add fruit and whipped cream. For savory, try a fried egg, bacon, or hot honey.