In a large bowl, preferably with a pour spout, toss the flour, oats, salt, baking powder, and cinnamon together. Set aside.

In another large bowl, whisk the egg and milk together. Whisk in the brown sugar and yogurt until no lumps remain. Whisk in the vanilla until combined. Pour the wet ingredients into the dry ingredients and gently whisk to combine. Make sure there are no patches of dry flour at the bottom of the bowl. The batter is thick and a few lumps are fine. Gently fold in any mix-ins you prefer.

Heat a griddle or large skillet over medium heat. Coat generously with butter or nonstick cooking spray. Once it’s hot, drop/pour a heaping 1/4 cup of batter on the griddle. Cook until the edges look set and you notice holes in the pancake’s surface around the border, about 2 minutes. Flip and cook the other side until cooked through, about 1–2 more minutes. Coat griddle/skillet with butter or nonstick spray again, if needed, for each batch of pancakes.

Keep pancakes warm in a preheated 200°F (93°C) oven until all pancakes are cooked. Serve pancakes immediately with toppings of choice.

Cover and store leftover pancakes in the refrigerator for up to 5 days.