Preheat waffle iron to medium heat. Spray well with non-stick cooking spray when heated.
Whisk together flour, baking powder, baking soda, salt and sugar. Mix together egg and milk and pour into dry ingredients. Whisk until well-combined and smooth.
Pour batter equally into waffle iron, allowing for the waffle to rise and spread slightly.
Remove from waffle iron and plate. You can also store on a baking sheet in a 250 degree oven until ready to serve if preparing a large batch of waffles.
For the Salted Caramel Apple Topping
Add brown sugar, butter and half-and-half to a large skillet or heavy-bottomed sauce pan. Melt over medium-low heat, whisking as needed. Remove from heat and add sea salt and vanilla. Stir in chopped apple. Set aside to cool slighty, about 2-3 minutes.
For serving
Place waffles on individual plates, top with apple slices and spoon salted caramel sauce on top of waffles.