Note: a reader felt better results were had by using 5 teaspoons of baking powder and subbing in melted butter for the milk!
Preheat the oven to 400°F, and grease a 12-cup muffin tin.
In a large bowl, whisk together the flour, sugar, baking powder, salt, and any add-ins. In a small bowl, lightly beat the egg. Add the oatmeal to the egg, and mash with a fork to break up any clumps. Add the oil, then 1/3 cup milk. Whisk to combine.
Pour the wet mixture into the dry mixture, and stir briefly to just combine. If batter is too thick, add a little more milk as needed to thin. Mixture should be quite thick but not so thick that it is difficult to stir in the dry ingredients.
Using a 1/3 cup scoop, divide the batter evenly between the wells of the prepared muffin tin. Sprinkle cinnamon sugar on top of muffins if desired.
Bake for 15 to 20 minutes, or until a toothpick inserted in the center of one of the muffins comes out clean. The muffins won’t brown much on top and might even look a little anemic if the cinnamon sugar isn’t used.
Note: It’s always going to be just a bit of a guess as to how much milk these muffins need and that depends how thick the oatmeal you use happens to be.
Keywords: Breakfast or Brunch Dish, leftover oatmeal, Muffins, Oatmeal