In a mixing bowl, whisk together yogurt, milk, eggs, sugar, and vanilla. In a separate mixing bowl, whisk together flour, baking powder, cornstarch, and salt.

Add dry ingredients to wet and whisk together. Do not over mix batter should be lumpy.

Preheat waffle iron and lightly grease with nonstick spray. Portion waffle batter into iron and cook according to manufacturer's instructions.

Melt butter in a medium sauté pan. Add apples and sugar. Let sugar dissolve and caramelize slowly over medium heat.

Once liquid in pan is reduced by half and apples are caramelized, remove from heat and hold at room temperature.

Whip heavy cream, powdered sugar, and vanilla extract until stiff peaks form. Then use a spatula to fold in yogurt.

Top waffles as desired with caramelized apples and whipped cream.