Preheat a 12-inch cast iron skillet over low heat with 1 teaspoon of butter or bacon fat in it. The pan should be steaming slightly before you put the cakes on it.
Put all of the ingredients in a high-power blender. Start off by adding just 1/2 cup of oat milk and blend until the batter is smooth. Stir in more oat milk to thin the batter to your desired consistency or leave the batter as is. It should be thick but pourable.
Pour the batter into the hot pan. For large pancakes, you should be able to fit 2 cakes in a 12" pan. Cook the pancakes for 45 seconds to 1 minute, waiting for tiny bubbles to form in the batter. Flip and cook for 1 more minute.
Continue to cook more cakes until the batter is gone. You may need to add more butter or bacon fat to the pan as you go. You may also need to periodically thin out the batter by adding a splash of oat milk or water.
Serve the pancakes warm with your favorite toppings or enjoy them cold as leftovers!