Preheat your oven to 400 F and line a 12-cup muffin tin with paper liners.
In a large bowl, combine the rolled oats and milk.
Add the maple syrup, neutral oil, brown sugar, and lightly beaten eggs to the oat mixture. Stir until well combined.
Gently stir in the flour, baking powder, ground cinnamon, baking soda, and kosher salt until just combined.
Divide the batter evenly between the prepared muffin tins. Sprinkle some sparkling or raw sugar on top if desired.
Bake in your preheated oven for about 18–25 minutes or until they spring back when lightly pressed.
Let the muffins cool in the tin for about five minutes before transferring them to a wire rack.