Whisk greek yogurt, eggs, milk, and vanilla extract together in a bowl. In a separate bowl combine flour, sugar, baking powder and salt.
Fold dry ingredients into wet with a flat spatula until just combined. Be careful not to overmix the batter.
Heat a waffle iron. When iron is warm, spray it with oil. Pour batter into the center of the iron and cook for about 2 minutes so the waffle is browned on the outside and cooked through in the middle.
Repeat this process until all of the batter is used. Be sure to spray with oil between each waffle so that they do not stick together.
Store in the fridge for up to 5 days or freezer for up to 3 months. Reheat in the toaster or toaster oven until warmed through. You can toast directly from frozen
Notes
**This recipe will make 18 mini waffles or 8 regular sized waffles