Directions

Make the waffles:
In a large bowl, whisk together the egg yolks with 1 cup of buttermilk.
In a separate medium bowl, whisk together the flour, sugar, baking powder, salt and baking soda. Add the dry ingredients to the bowl with the eggs, stirring just until combined.
Add the remaining 1 cup buttermilk, melted butter and vanilla extract to the bowl, stirring just until combined. (The batter will be lumpy.)
Add the egg whites to the bowl of a stand mixer fitted with the whisk attachment. Beat the egg whites at medium-high speed until stiff peaks form. Fold the egg whites into the batter then cover the batter and allow it to rest at room temperature for 30 minutes. While the batter rests, make the strawberry syrup. (Recipe follows.)
When ready to serve, preheat your waffle iron according to the manufacturer’s directions and lightly grease it with cooking spray. Pour a portion of the batter into the heated waffle iron and cook the waffle to your desired doneness. Top the waffles with strawberry syrup and serve immediately.
Make the syrup:
In a medium saucepan set over medium heat, combine the strawberries, sugar, lemon juice and lemon zest. Bring the mixture to a boil then reduce it to a simmer and continue cooking, stirring occasionally, until the strawberries are soft and the liquids have thickened slightly, about 15 minutes.
Transfer the syrup to a serving bowl and set it aside to cool slightly. The syrup will thicken as it cools. (Optional: If you prefer a thinner syrup, strain the cooked mixture through a mesh sieve to remove larger pieces of strawberry.)