In the bowl of a food processor or blender, process the oats, sugar, baking powder, and salt until the oats are finely ground, up to a full minute based on your machine. , Add the remaining ingredients and process until everything is well combined, about 30 seconds.  , Let the batter rest, uncovered, for 15 minutes at room temperature; it will thicken slightly.    , Meanwhile, heat a large skillet over medium heat, or set an electric griddle to 325°F. Grease the surface with oil or butter.  , Spoon the batter a generous 1/4 cup at a time onto the hot surface; a scone and muffin scoop works well here.  , Cook until golden brown on the bottom, about 3 minutes; the tops may develop a few bubbles. Flip and cook the pancakes until the second side is golden brown, about another 3 minutes. Serve immediately.  , Store leftover pancakes, well-wrapped individually, in the freezer for up to 1 month. Thaw and reheat in the toaster or in a 250°F oven until warmed through.