01 - Preheat the waffle iron according to the manufacturer's instructions.
02 - In a blender or food processor, pulse rolled oats until finely ground.
03 - In a large bowl, mix ground oats, all-purpose flour, brown sugar, baking powder, baking soda, salt, and ground cinnamon.
04 - In a separate bowl, whisk together eggs, milk, melted unsalted butter, and vanilla extract until well combined.
05 - Pour the wet mixture into the dry ingredients and stir until just combined. Allow batter to rest for 5 minutes to thicken.
06 - Lightly grease the preheated waffle iron with oil or non-stick spray.
07 - Pour approximately 1/2 cup of batter into the waffle iron per waffle, adjusting for appliance capacity.
08 - Cook waffles for 3 to 5 minutes, or until golden brown and crisp, following your manufacturer's instructions.
09 - Serve warm with preferred toppings such as maple syrup, fresh fruit, or yogurt.