Preheat your oven to 200°F to keep the waffles warm and crisp. Preheat your waffle maker as well.
In a large mixing bowl, combine the all-purpose flour, baking powder, sugar, and cornstarch. Stir gently to mix.
In a separate medium bowl, whisk together the eggs, Greek yogurt, vanilla extract, and milk until smooth and combined.
Make a well in the center of the dry ingredients. Pour the wet mixture into the well and stir gently until just combined. Be careful not to overmix.
Pour about 1/2 cup of batter into the preheated waffle maker and cook according to the manufacturer's instructions, usually for 3-5 minutes, until golden brown and crispy.
As you cook the waffles, place the finished ones directly on the oven rack to stay warm and crispy.
Serve the waffles with your choice of toppings like whipped cream, fresh fruit, syrup, powdered sugar, or nut butter.