Add the oats to a food processor and blend until you get a fine flour. It should give you about 2 cups. Add the oat flour to a large bowl with the sugar, baking powder, baking soda, salt and cinnamon, whisking together.
Whisk in the buttermilk, eggs, butter and vanilla extract until just combined.
Lightly grease a non-stick pan with oil over medium heat. Pour ⅓ cup of the batter onto the hot griddle. Cook until you see bubbles on top and the edges are firming up. Flip and cook for another 1-2 minutes until the pancakes are browned and cooked through. Serve warm with butter, fruit and maple syrup.
Notes
Since there is no gluten, you can throw all of the ingredients in the blender and blend together if you prefer.
DO NOT let the pancake batter sit out or the oats will soak up the liquid and thicken too much. Add more buttermilk if you do.
Oat flour pancake batter is thinner than traditional pancake batter. However it shouldn't be runny. If it is too thin, add 1 tablespoon of oats at a time and blend until reaching desired consistency. If it's too thick, then add 1 tablespoon of buttermilk milk at a time and blend.
Use an electric skillet which allows you to make multiple pancakes at a time, but you can use a cast iron skillet as well.
Waituntil bubbles pop and form holes that stay open on the surface of the batter before flipping the pancakes.
Heat oven to 200°F and place pancakes on a baking sheet to keep warm wan cooking additional pancakes.