Preheat a waffle iron according to the manufacturer’s instructions.
Into a medium bowl, sift the flour, baking powder, and salt.
In a separate bowl, beat together the egg yolks and sugar until the sugar is completely dissolved and eggs have turned a pale yellow. Add the milk, melted butter, and vanilla extract and whisk to combine. Add the flour mixture to the egg-milk mixture and whisk just until blended. Do not overmix.
In a third bowl, beat the egg whites with an electric mixer until soft peaks form, about 1 minute.
Using a rubber spatula, gently fold the egg whites into the waffle batter, being careful not to overmix.
Coat the waffle iron with nonstick cooking spray, if required, and pour enough batter in the iron to just cover the waffle grid. Close and cook as per the manufacturer’s instructions until golden brown, 2 to 3 minutes. (Do not open the waffle iron for at least 1 minute.) Repeat with the remaining batter.
Serve immediately with Strawberry Syrup spooned over the top of each waffle.
Fresh Strawberry Syrup: In a medium saucepan, combine all the ingredients and bring to a boil. Lower the heat and simmer until the strawberries are soft and the syrup is thickened and reduced by one-third to one-half in volume, 15 to 18 minutes.
Remove from the heat and let cool to room temperature before serving. (If thinner syrup is desired, strain the hot syrup through a fine mesh strainer into a clean container and let cool.).