In a medium bowl, mix the oat flour, corn flour, baking powder, cinnamon, nutmeg and sugar until well combined.
Add the vanilla, egg, olive oil and oat milk and stir thoroughly to combine. This will be a thick, cake-like batter.
Melt the butter in a non-stick frying pan (or use a griddle) and heat until hot.
Ladle about ¼ cup batter per pancake into the frying pan and cook over medium heat until the batter is full of bubbles and the side laying on the pan is nice and brown, about 15 minutes.
Flip the pancakes over and continue cooking about another 10 minutes until the second side is nicely browned.
Serve with fresh fruit or maple syrup.
Notes
Note 1: Be sure to cook the pancakes until the whole top is full of bubbles or they will be somewhat gummy, rather than simply dense.Note 2: Gluten-free flour tends to react to baking powder more vigorously than regular flour. If your batter becomes too thick, add a little more milk to thin the batter to a normal pancake batter consistency.