In a large mixing bowl, combine the all-purpose flour, whole wheat flour, oats, baking powder, baking soda, and ground cinnamon. Whisk these dry ingredients together until they are well mixed.
In another bowl, whisk together the milk, Greek yogurt, honey, eggs, melted butter, and vanilla extract until smooth and creamy.
Pour the wet mixture into the bowl with the dry ingredients. Gently fold the two mixtures together with a spatula until just combined. Be careful not to overmix; a few lumps are perfectly fine!
Preheat your waffle iron according to the manufacturer's instructions. Lightly grease it with a bit of cooking spray or melted butter to prevent sticking.
Once the waffle iron is hot, pour an appropriate amount of batter onto the center of the iron (usually about 1/2 to 3/4 cup, depending on your waffle iron size). Close the lid and cook until the waffles are golden brown and crisp. This typically takes around 4-5 minutes.
Carefully remove the waffles from the iron and serve immediately with maple syrup or a drizzle of honey. Top with fresh fruits, nuts, or a dollop of whipped cream for an extra special touch!
